Arsenal's Premier League title hopes suffered a devastating blow as they threw away a two-goal lead for the second week running to draw 2-2 with West Ham United at the London Stadium.
Gabriel Jesus and Martin Odegaard put Mikel Arteta's side two goals to the good inside the opening 10 minutes, but Said Benrahma and Jarrod Bowen responded either side of a missed Bukayo Saka penalty for the relegation-threatened Hammers, who capitalised on another Arsenal collapse to give Manchester City a helping hand in the race for glory.
A few meaty challenges flew in from those in claret and blue during the early exchanges, but as was the case against Newcastle, the Hammers' backline was carved open at will.
It took Arsenal just seven minutes to draw first blood, as an intricate passage of play around the penalty area ended with Odegaard slipping in Ben White, who squared for Jesus to tap home at the back post.
David Moyes's backline barely had time to regroup before they were breached again, as Gabriel Martinelli's cross to the back post was on the money for Odegaard, who ghosted in unchallenged to volley home in the 10th minute to put Arsenal in cruise control.
West Ham were being made to pay for comical defending, but rather than going for more, Arsenal were content to knock the ball around as the game approached the half-hour mark, with West Ham showing little signs of a revival.
However, as complacency crept in for Arsenal, West Ham gave themselves a lifeline out of nowhere, as Thomas Partey gave the ball away to Declan Rice in a dangerous area - the Ghanaian stopped and appealed for a handball against the Hammers' captain, which fell on deaf ears.
Rice advanced into the box and cut back for the onrushing Lucas Paqueta, who went down under a challenge from Gabriel Magalhaes, and David Coote wasted no time in pointing to the spot in the 33rd minute.
Four months after scoring from the spot at the Emirates Stadium, Benrahma sent Aaron Ramsdale the wrong way from 12 yards to cut the deficit in half, and there were shades of Anfield for Arteta's side as West Ham suddenly sprung into life.
The Gunners got to half time with their slender lead intact, and it was their turn to step up to the penalty spot in the 52nd minute, as Michail Antonio was penalised for handball.
However, in similar fashion to Mohamed Salah's missed attempt last week, Saka sent his spot kick wide, and West Ham took full advantage of that reprieve only two minutes later.
Arsenal failed to adequately clear a throw in, allowing Thilo Kehrer to loft the ball back in for Bowen, and a stagnant Arsenal defence were powerless to stop the Englishman volleying home - Ramsdale may have felt that he should have done better, though.
The visitors' attempts to restore their lead were futile, and West Ham came agonisingly close to stealing all three points in the 82nd minute, as Antonio struck the bar with a header from a tight angle.
Arsenal have famed themselves on dramatic late goals this season, but Arteta's cavalry could not produce something similar in five minutes of injury time and may very well be ruing the result of this London derby come next month.
The Gunners are four points ahead of Manchester City having played a game more, and they return to the Emirates to face Southampton on Friday, while West Ham stay 15th - four clear of the drop zone - and Moyes's men now prepare to host Gent in the second leg of their Europa Conference League quarter-final on Thursday. body check tags ::