The Premier League side enjoyed almost total dominance on Thursday but relied on goalkeeper Sean O'Neill's mistake to allow Vinagre to give them breathing space in their second round qualifier.

Nuno Espirito Santo was not totally convinced by Wolves (Nick Potts/PA)

They go to Belfast for next week's second leg expected to progress – but Nuno wants improvement.

"It (a second goal) makes a difference, no doubt, but we have to look at the game and what moment we are in," said Nuno.

"Crusaders are well organised, they were deep and there was no space but we need to be faster, more accurate and sharper. All these things will come with hard work.

"It was tough, the players did a fantastic job. It was very hot and the idea of the game was there. I am proud of them.

"We cannot be frustrated. With set-pieces we must improve, we touched the ball but didn't have enough chances."

Jota opened the scoring eight minutes before the break when he crashed in a half-volley from Adama Traore's cross.

The striker had already dragged wide while Leander Dendoncker and Moutinho had efforts saved by O'Neill.

The one-way traffic continued after the break and Wolves, watched by Real Madrid centre-back Jesus Vallejo ahead of his expected loan deal, introduced £32million striker Raul Jimenez midway through the second half.

Wolves were playing their first game in Europe for 39 years (Nick Potts/PA)

But it was fellow substitute Vinagre, fresh from signing a new five-year contract on Wednesday, who added a second deep in stoppage time, tapping in when O'Neill dropped Moutinho's cross.

Crusaders boss Stephen Baxter said: "It's the best performance they've given us – I played here for six years and have managed for 14. It's the best performance for almost 20 years.

"In the last 20 seconds you don't want to be conceding another but I'm very proud of the team.

"When the opposition manager says, 'bravo, your team were superb tactically' you have to take that as a compliment.