Arsenal suffered another dose of the title jitters as West Ham came from two goals down to draw 2-2 at the London Stadium.
The Premier League leaders raced into a two-goal lead inside the opening 10 minutes through Gabriel Jesus and Martin Odegaard but just as they had against Liverpool last weekend, they faltered badly.
Not that anyone realistically expected West Ham to pull off a similar escape act towards the end of a season of underachieving and battling relegation.
But Said Benrahma’s penalty and Jarrod Bowen’s volley, either side of a missed spot-kick by Bukayo Saka, rescued a surprise point for the hosts and put another dent in Arsenal’s title bid.
It took just six minutes for the visitors to take the lead, as Thomas Partey and Saka toyed with West Ham on the edge of the area before feeding Ben White down the right.
The defender reached the byline and squared the ball for Jesus to tap into an empty net.
Four minutes later the Gunners carved West Ham open again, Gabriel Martinelli crossing for the unmarked Odegaard to volley past Lukasz Fabianski.
Arsenal were cruising, yet West Ham were handed a lifeline when Declan Rice intercepted Partey’s weak clearance and, amid cries of handball, squared the ball to Lucas Paqueta in the area.
Gabriel’s foul on the Brazilian midfielder gave referee David Coote the easiest of penalty decisions to make and Benrahma rolled the spot-kick home.
The goal lifted the Hammers, and the mood of a previously apathetic home crowd and Michail Antonio’s header forced Aaron Ramsdale into a save before Paqueta volleyed over.
West Ham had only trailed Newcastle 2-1 at half-time in their last home match, but conceded 20 seconds into the second half on their way to a disheartening 5-1 defeat.
They avoided that ignominy this time and lasted until the 50th minute before Martinelli’s shot struck Antonio’s stray arm in the area.
England winger Saka stepped up to surely win the game for Arsenal, only to fire his spot-kick horribly wide.
West Ham promptly went up the other end and equalised, Bowen sweeping the ball home first time from Thilo Kehrer’s up-and-under.
Saka should have punished some slack defending when he raced through on goal only to scuff his shot straight at Fabianski.
But it could have been even worse for Arsenal as West Ham chased an unlikely winner, Antonio meeting Benrahma’s cross with a far-post header which clipped the crossbar to leave the Gunners grateful for a point.