West Brom's Premier League relegation was confirmed as Arsenal returned to winning ways to sink Sam Allardyce's side.
The Baggies are the eighth club Allardyce has managed in the Premier League but a 3-1 defeat at the Emirates Stadium means the former England boss has been relegated from the division for the first time.
The writing had been on the wall for some time and, despite a good start here, goals from Emile Smith Rowe and Nicolas Pepe had them on the ropes. Matheus Pereira reduced the arrears with a memorable strike but Willian's first Arsenal goal from a late free-kick sealed the Baggies' fate.
For the hosts, this was a positive response to their Europa League semi-final exit at the hands of Villarreal on Thursday night and just about kept alive their hopes of securing European football in some guise next season.
It is an indictment of Arsenal's own league campaign that, if West Brom had won in north London, they would have moved closer in the table to the Gunners than Mikel Arteta's men are to second-placed Manchester United.
But it was not to be as West Brom returned to the Sky Bet Championship after one season back in the top flight.
Pereira went agonisingly close top putting the visitors ahead with their first opening of the game, bending a strike inches wide of Bernd Leno's goal with the Germany international beaten.
Callum Robinson was recalled to the Baggies side and hit the crossbar soon after, only to see the offside flag raised.
Allardyce's team were certainly on top and Pereira whistled another effort wide as they looked to give themselves an early lead.
Bukayo Saka, operating at left-back for the hosts, was once again the bright spark in their side and saw penalty appeals waved away after he broke into the box and was well challenged by Darnell Furlong.
West Brom may have created the best of the early openings but it was Arsenal who would break the deadlock, Smith Rowe slotting home from a Saka cross just before the half-hour mark for his first Premier League goal.
The home team's lead was doubled six minutes later, Pepe cutting in from the right flank and curling home a fine effort.
Albion responded after the break and refused to go down with a whimper, Pereira running the full length of the Arsenal half before scoring past Leno to half the deficit.
But, while Allardyce had never previously tasted Premier League relegation, he failed to record a first-ever away win against Arsenal as a manager as a superb Willian free-kick in the last minute secured the points for the hosts.
It remains to be seen if the 66-year-old will stay in place to lead the charge for an instant return to the top tier.
His counterpart will, at least, have enjoyed a first home win since beating derby rivals Tottenham on March 14 – with Arteta still mathematically able to guide Arsenal into Europe's lesser competitions come the end of the campaign.
