Mikel Arteta's men had to be patient for their first of the afternoon, but after William Saliba headed home from a corner, the Gunners ran riot, as Bukayo Saka, Gabriel Magalhaes and Leandro Trossard also found the mark in a first-half demolition job.
Thousands of West Ham supporters had already left the ground in time for the second half, where Saka notched his second of the afternoon before former Hammer Declan Rice completed the obliteration against his erstwhile employers, who were condemned to their heaviest Premier League home win ever.
On the other hand, an electrifying Arsenal side have won a Premier League away match by a six-goal margin for the very first time, with their previous bests on the road being 6-1 successes over Middlesbrough in 1999 and a David Moyes-led Everton side in 2009.
The Arsenal squad had a particularly thin feel to it at the London Stadium, as none of Emile Smith Rowe, Takehiro Tomiyasu, Gabriel Jesus or Oleksandr Zinchenko was present, while Jorginho - last weekend's man of the match against Liverpool - was dropped to the bench due to an unspecified issue.
In contrast, West Ham lined up unchanged from their loss to Manchester United and were comfortably keeping Arsenal at bay inside the opening 20 minutes, where the Gunners' only real chance of note was a deflected Bukayo Saka strike which sailed behind.
West Ham showed a couple of flickers of life on the counter themselves, although nothing that gave David Raya too much to think about, and the hosts then had to weather a sudden Arsenal storm.
Within the space of two minutes, Trossard saw two promising openings pass him by, as he firstly headed over the bar from Saka's cross in the 22nd minute before connecting sweetly with a volley inside the box, but Alphonse Areola was equal to it with a brilliant acrobatic stop.
It only seemed like a matter of time before Arteta's men broke the deadlock, though, and true enough, the visitors would draw first blood in the 32nd minute, as a deep Rice corner was on the money for Saliba to head home from inside the six-yard box.
Arteta's men did not let up after taking the lead and should have doubled their advantage in the 35th minute, as Jakub Kiwior delivered a fine outswinging cross for Saka, but the 22-year-old's header excruciatingly bounced just wide.
Saka's agony continued just two minutes later, as he was slipped in down the right by Martin Odegaard and delicately lifted the ball over Areola, but his attempt also trickled beyond the far post and behind the goal.
However, the winger's luck was finally in seconds after that second wasted chance, as he latched onto Trossard's inch-perfect ball over the top - staying just onside in the process - and was brought down by Areola as he tried to skip past the Frenchman.
Craig Pawson immediately pointed to the spot, and Saka dusted himself down before emphatically sending Areola the wrong way to deservedly double the visitors' advantage, and West Ham's alarming capitulation showed no signs of stopping just before the break.
With 44 minutes on the clock, another Rice delivery - this time from a free kick on the left-hand side - caused carnage in the Hammers box, and Gabriel charged in to head home at Areola's post.
Irons fans were already heading for the turnstiles en masse as seven minutes of injury time went up on the board, the second of which saw Arteta's rampant troops make it four, as Odegaard laid off Trossard just inside the box, and the Belgian shifted the ball onto his right foot before finding the top corner with panache; Areola got a hand to his attempt but was ultimately powerless.
As excellent as Arsenal were, Moyes's men had been utterly appalling since conceding the opener - the fans let them know as such at the break - although the last time that Arsenal had led a Premier League away game by four goals, Newcastle United produced an outrageous comeback to draw 4-4 in 2011.
Kalvin Phillips and ex-Arsenal man Dinos Mavropanos were called upon to try to resurrect a bruised and battered West Ham team - Edson Alvarez and Kurt Zouma were the half-time casualties - but the visitors continued to dominate proceedings after the restart.
Saka makes it five, Rice makes it SIX...— Sky Sports Premier League (@SkySportsPL) February 11, 2024
How many goals are Arsenal going to score here?! 😳 pic.twitter.com/LjBoBto7g3
Areola stuck up a strong hand to deny Saka his second in the 58th minute, but the England international would not have to wait too much longer for his 10th Premier League goal of the season, picking up a slick pass from Odegaard, beating Nayef Aguerd all ends up and leaving Areola rooted to the spot with a powerful finish inside his near post in the 63rd minute.
If salt had not already been rubbed into the Hammers' wounds, it certainly was in the 65th minute, as after some miscommunication between Trossard and Odegaard saw the ball roll past both of them, Rice arrived on the scene and thundered a ferocious 25-yard strike into the top corner.
The ex-Hammers captain unsurprisingly did not celebrate in front of his former adoring fans, some of whom applauded him as he was substituted just seconds later, while others made more unsavoury gestures towards the Englishman.
The seldom-seen Mohamed Elneny - who had replaced Rice - tried to add to his catalogue of long-range goals from a similar position in the 72nd minute, but his strike was straight down the throat of Areola.
With the contest slowing to a crawl, Arteta offered some valuable minutes to Ethan Nwaneri - the 16-year-old making just his second Premier League appearance after becoming the youngest player in the competition's history last season.
The Gunners would not quite achieve seventh heaven at the London Stadium, meaning that they remain behind Manchester City in third place, but only adrift of the champions on goals scored by virtue of extinguishing the chasm in goal difference.
Arsenal have a week to celebrate and recuperate before Burnley visit the Emirates next Saturday, the same day that West Ham - who stay eighth - try to respond away to Nottingham Forest.No Data Analysis info