Arsenal slipped to a shock 2-1 defeat against Dinamo Zagreb in their opening Champions League group stage match.
The Gunners fell behind when Alex Oxlade-Chamberlain turned the ball into his own net after Josip Pivaric's shot was saved by David Ospina.
Olivier Giroud was then sent off for picking up a second booking, before Junior Fernandes headed in from a corner to double Zagreb's lead.
Theo Walcott pulled a goal back when he raced onto Alexis Sanchez's through ball and slotted in, but the Gunners were unable to find an equaliser as their European campaign began on a losing note.
Find out the action unfolded below.
Hello everyone! The Champions League made a welcome return last night with the first matchday of this year's group stage. There was plenty of excitement and some great goals, but the action is not over as 16 more teams get their campaigns underway this evening.
We are ready for #ZAGvAFC at Stadion Maksimir, are you? pic.twitter.com/4iOpshFbym
— Arsenal FC (@Arsenal) September 16, 2015
One of those teams hoping to make a strong start are Arsenal, who have struggled to achieve their full potential in Europe over the years. They have been knocked out in the last 16 for the past five seasons, but they will fancy their chances of making it out of the group with Bayern Munich.
The Gunners are up against Croatian champions Dinamo Zagreb, who are back in the group stage after a three-year absence. However, they have never made it to the knockout rounds in the competition and have not won a group match in 16 years.
Right, it's time to check out the team news from the Stadion Maksimir, where Arsene Wenger has made quite a few changes to his starting XI...
DINAMO ZAGREB XI: Eduardo, Pinto, Sigali, Taravel, Antolic, Machado, Ademi, Pivaric, Soudani, Fernandes, Pjaca
ARSENAL XI: Ospina, Debuchy, Gabriel, Koscielny, Gibbs, Arteta, Cazorla, Oxlade-Chamberlain, Ozil, Sanchez, Giroud
DINAMO ZAGREB SUBS: Jezina, Benkovic, Matel, Coric, Rog, Henríquez, Hodzic
ARSENAL SUBS: Cech, Monreal, Chambers, Flamini, Coquelin, Walcott, Campbell
There we have our teams for this evening's match, and Arsenal have made a total of six changes to the side that beat Stoke at the weekend. David Ospina, Mathieu Debuchy, Kieran Gibbs, Mikel Arteta, Alex Oxlade-Chamberlain and Olivier Giroud are the players who come in to start.
Meanwhile, Marko Pjaca is chosen to lead the line for the visitors, with El Arbi Hillel Soudani and Junior Fernandes joining him in the attack. However, former Manchester United striker Angelo Henriquez having to settle for a place on the bench.
So, the Gunners will get their European campaign started this evening, off the back of a decent opening to the Premier League season. There was doom and gloom on the opening day as they lost at home to West Ham, but they have since recovered to win three of the last four games and move up to fourth in the table.
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Arsene Wenger will also hope that his team can find their goalscoring form, as they have only scored five goals in their five league matches. They did score twice in a win over Stoke at the weekend, but they had 29 efforts on goal and missed some huge chances to make the game safe.
Many supporters feel that the club should have signed another forward over the summer, with Theo Walcott and Olivier Giroud their only striking options at the moment due to a long-term injury to Danny Welbeck. It is worth remembering though that this is the same team who defended the FA Cup last season and put together a superb eight-game winning run in the second half of the campaign.
One thing that has eluded the club in recent years is European success, and Arsene Wenger has admitted that he is desperate to win the Champions League. This will be their 16th successive season in the group stage of the competition, but they have only reached the final once, suffering a heartbreaking defeat to Barcelona in 2006.
In recent years they have not made it past the round of 16, and last season they were beaten by Monaco. It looked like a promising draw for the Gunners, but they slipped to a poor 3-1 home defeat. Despite goals from Olivier Giroud and Aaron Ramsey in the return leg, it was not enough, as they were dumped out on away goals.
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They suffered the same fate three seasons ago, when Bayern Munich came to the Emirates and earned a 3-1 win. The Gunners won the next leg 2-0 in Germany, but again they went out on away gaols after a 3-3 draw. A year before that Wenger's side were beaten 4-0 by AC Milan in Italy, and despite winning 3-0 at home, they could not find another goal to secure what would have been a stunning comeback.
Taking on Arsenal this evening are a Dinamo Zagreb side who have returned to the group stage of the Champions League for the first time in three seasons. They are the biggest side in Croatia, having won ten league titles in a row, but they have failed to reproduce that form in Europe.
The club have never made it to the knockout stages of the Champions League and have lost 11 of their previous 12 group games. However, they did manage to end their poor losing run with a 1-1 draw against Dynamo Kiev in their last group fixture in December 2012.
These two teams faced each other in the third qualifying round of the Champions League nine years ago. It was Arsenal who came out on top in the first leg, with a double from Cesc Fabregas and a strike from Robin van Persie securing a 3-0 win.
In the return meeting Eduardo, who would join the Gunners the next summer, gave his team hope of pulling of a shock with an early goal. However, Freddie Ljungberg headed in an equaliser and Mathieu Flamini scored a last-minute winner to secure a 5-1 aggregate win.
There's plenty of European action taking place this evening, and we've got it all covered for you live. Arsenal and Zagreb fans will also be keen to know what is going on in the other Group F match, as Bayern Munich travel to Greece to take on Olympiacos.
We are now just three minutes away from the start of tonight's match, and the teams have just emerged onto the pitch at the Stadion Maksimir. The Arsenal fans are making plenty of noise and have travelled in great numbers to support their side this evening.
KICKOFF! We are underway in Zagreb!
Arsenal have made a strong start to the match and they have seen all of the ball in the opening minutes. They are also finding space down the flanks, with the home side being pushed deep inside their own box.
It's still all Arsenal, and Dinamo have barely had a touch of the ball so far this evening. The Gunners are working it around nicely between their midfielders, as they look for gaps to open up in their opponents' defence.
SHOT! For all of Arsenal's possession, Dinamo have the first effort of the match as they break forward in numbrs. Pjaca eventually picks up the ball and hammers in a strike from range, but his shot flies well wide of Ospina's goal.
SAVE! What a superb save this is from Eduardo. Giroud rises above everyone inside the box to meet a corner from Cazorla and looks to plant a header into the top corner. The ball looks certain to find the net, but the Dinamo keeper is there to push the ball behind.
SHOT! The Arsenal defence will have to keep an eye on Pjaca, as he has looked lively in these early stages. He threatens again when he works some room on the edge of the box and turns into space, before drilling a strike off target.
Dinamo are almost playing as the away side this evening, as they are getting plenty of men behind the ball and waiting for their chance to hit the Gunners on the counter. They do have some pacy players in forward areas and have already shown glimpses of the danger they could cause.
Giroud almost has a chance for Arsenal when he is picked out inside the box and looks to get the ball onto his left foot. However, as he gets ready to shoot, Taravel comes across and makes a fine tackle to stop his fellow Frenchman in his tracks.
CHANCE! Eduardo made a great save to deny Giroud earlier tonight and he has made an even better stop here. Oxlade-Chamerlain drives to the byline and flashes a great cross into the box. Giroud arrives to meet it and turns his header onto the post, before Eduardo gets down quickly to block the striker's follow up from point-blank range.
SHOT! Dinamo have not been afraid to shoot from range, and Antolic has their latest effort on goal. It is not the best effort through, as once again the hosts fail to hit the target with Opsina left untroubled.
YELLOW CARD! Giroud is shown a card by the referee for his complaints after a free kick was given against him.
GOAL! Dinamo Zagreb 1-0 Arsenal (Alex Oxlade-Chamberlain own goal)
For all of their early dominance, Arsenal find themselves behind to the Croatian champions. Their defence is split open, as Pivaric races onto a pass from Soudani, before seeing his effort saved by Ospina, but the ball ends up hitting Oxlade-Chamberlain and dropping into the back of his own net.
That goal will be a shock to the system for Arsenal, who have looked in control for much of this opening half. Their defence was cruelly exposed, but Oxlade-Chamberlain could have done little about the goal, although he did allow Pivaric to run in behind him too easily.
Arsenal have come out strongly since conceding and are pushing plenty of men forward in search of a quick equaliser. Should Dinamo manage to hold on and claim a famous win, then Wenger's decision to make so many changes may be heavily criticised.
Two of the changes made by the Gunners have been at the back and they have looked quite open down the flanks. I did mention that Zagreb have a lot of pace in the attack and they will look to soak up more pressure and break quickly as the game wears on.
The Gunners are lacking a real cutting edge at the moment and they are not causing the hosts enough problems. Even when they do get into good areas, there are not enough players inside the box, and Zagreb are able to clear with ease.
RED CARD TO ARSENAL! Things go from bad to worse for Arsenal, as Giroud is sent off with five minutes left of the first half. The Frenchamn's first booking was for complaining, while his second card is for a late challenge on Pinto. It was not the worst tackle, but Giroud was walking a tightrope and his team have it all to do now.
Wenger is absolutely fuming on the touchline, as his team allow Zagreb to get down the line far too easily. The Arsenal manager has some big decisions to make at the break, as his team try to avoid a nightmare start to Champions League campaign.
There will be just one minute added on before the break.
HALF-TIME: Dinamo Zagreb 1-0 Arsenal
The whistle blows for half time in Zagreb, and Dinamo have a surprise lead over 10-man Arsenal. An unfortunate own goal by Alex Oxlade-Chamberlain gave the Croatians the breakthrough, before Olivier Giroud was dismissed for picking up two yellow cards.
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Arsenal enjoyed plenty of possession in the opening 45 minutes and saw a commanding 67% of the ball. They also had eight shots, but Dinamo showed their threat in the attack too, and crafted seven attempts on the visitors' goal.
So, what can Arsenal do to turn this around? They will be wary of making too many attacking changes, due to their numerical disadvantage, but Arsene Wenger will surely turn to Theo Walcott at some point this evening. The striker famously scored a hat-trick for England in a 4-1 win against Croatia at this very stadium in 2008.
RESTART! Zagreb take the kick off and get the match back underway.
MISS! Arsenal almost find themselves two goals down just moments after the break when Oxlade-Chamberlain flicks the ball onto his own post from a corner. The ball then bounces back out and hits Soudani, before trickling inches wide of the post with Ospina left stranded.
YELLOW CARD! Antolic picks up Dinamo's first booking of the evening for a foul on Ozil.
CHANCE! The Gunners come close to getting back on level terms when Ozil is picked out in the middle by Gibbs. The German then tries to send a low strike into the far corner, but Eduardo spreads himself well to make another fine save.
Arsenal are on top at the moment and they are getting into some dangerous areas. The hosts are hanging on a bit, and only a string of last-ditch tackles and some good goalkeeping has helped them to retain their lead.
GOAL DISALLOWED! Ozil has the ball in the back of the net for Arsenal, but it is chalked off by the linesman. He had raced onto Oxlade-Chamberlain's threaded pass and slotted a tidy effort into the corner, but he was clearly standing in a offside position.
There has been a goal in tonight's other Group F match and it's Bayern who have the lead over Olympiacos. Thomas Muller has scored the goal in Greece as the German champions look to make a winning start to their European season.
GOAL! Dinamo Zagreb 2-0 Arsenal (Junior Fernandes)
Fernandes had just been denied a clear shot on goal by a brilliant challenge by Debuchy, but he scores from the resulting corner with a towering header past Ospina. The marking was almost non-existent from the Gunners and there is a long way back for them in this match now.
Dinamo have been buoyed by that second goal and they are working the ball around nicely inside the Arsenal half. A third goal would really kill of the tie and they look the side more likely to score next.
SUBS! Arsenal make a triple change, with Walcott, Campbell and Coquelin coming on to replace Arteta, Oxlade-Chamberlain and Gibbs.
YELLOW CARD! Pinto is shown a card for bringing down Sanchez just outside the box with a crunching challenge.
SHOT! Sanchez steps up to take the resulting free kick, but he bends it high and wide of the target. The Chilean has not hit top form yet this season and has not scored for Arsenal since his stunning goal in the FA Cup final.
Walcott almost has a chance for Arsenal when he bursts through on goal and sees an effort stopped by Eduardo. However, the flag was up against the England international and the keeper is down and receiving treatment after making the initial save.
SUB! Dinamo make their first change of the match, with 18-year-old midfielder Coric coming on for the goalscorer Fernandes.
The Gunners are struggling to get on the ball at the moment, and Dinamo are looking comfortable at the back. They have not come under too much pressure since the opening minutes of this half, but they will have to keep an eye on Walcott.
GOAL! Dinamo Zagreb 2-1 Arsenal (Theo Walcott)
On the same ground that he scored a hat-trick on seven years ago, Walcott pulls a crucial goal back for Arsenal. He shows great pace to beat the defence and latch onto Sanchez's pass, before keeping his composure to slide an effort beyond Eduardo and into the far corner.
Walcott almost has another chance when he races into the box to meet Campbell's cross from the right. He manges to get a flick to the ball, but he is unable to get enough power on his header as Eduardo makes a comfortable save.
SUB! It's another change for the hosts, with Rog coming on for Antolic.
The hosts are looking slightly nervy at the back, as they desperately try to cling on to what would be their first group stage win in 16 years. Walcott's pace has caused their defence real problems and they are bound to come under more pressure in the remaining minutes.
YELLOW CARD! Campell picks up a booking for dragging down Pjaca from behind.
SUB! Dinamo make their third and final change of the evening, with Pjaca heading off to be replaced by Benkovic.
YELLOW CARD! Rog brings down Campbell deep inside the Arsenal half and is shown a card by the referee.
There are going to at least five minutes of stoppage time. Will it be enough for Arsenal to grab a late equaliser?
It's just not happening for the Gunners, and Gabriel loops a header over the bar from a Sanchez cross. They are piling plenty of men into the box, but Zagreb are dealing well with threat and are being cheered on by a passionate home crowd.
FULL-TIME: Dinamo Zagreb 2-1 Arsenal
Zagreb manage to hold on to their lead after five minute of stoppage time to claim a famous win over Arsenal. The Croatian champions have won their first group stage match in 16 years, while the Gunners will reflect on another poor night in Europe.
That's it for our coverage this evening. We'll have analysis and player ratings to follow, so stay tuned for that, while there will be more continental action tomorrow night, as the group stage of the Europa League kicks off. Until then, goodbye!
