Arsenal spurned the opportunity to retake first place in the Premier League as they lost 2-0 to fellow Londoners West Ham United at the Emirates.
West Ham only had three efforts on target, but Tomas Soucek gave them a halftime lead before former Arsenal defender Konstantinos Mavropanos extended the advantage after the break.
Arsenal had more than twice as many chances but failed to take any as the visitors defended gamely.
West Ham took the lead against the run of play after 13 minutes when Soucek knocked home after a pull-back from Jarrod Bowen who looked as if he just managed to keep the ball in play.
After that it was an Arsenal blitz with Bukayo Saka crashing the ball against the post and Gabriel Jesus missing two good opportunities before Mavropanos scored with a thumping header from a James Ward-Prowse corner in the 55th.
West Ham could have made it three from three chances but Said Benrahma had a penalty saved in added time after a foul by former West Ham captain Declan Rice.
Second-placed Arsenal remain on 40 points, two behind Liverpool who beat Burnley 2-0.
Elsewhere, Tottenham Hotspur's top-four ambitions suffered a blow as they lost 4-2 at Brighton & Hove Albion with only a late rally saving them from their heaviest defeat since Ange Postecoglou became manager.
Victory would have put injury-hit Spurs above Manchester City into fourth, but they were mauled on the south coast as a Brighton side also missing key players ran riot.
A powerful early strike by Josh Hinshelwood and Joao Pedro's penalty gave the hosts a deserved 2-0 lead at halftime as Tottenham struggled to deal with Brighton's intensity.
The visitors responded in the second half with Richarlison having a goal disallowed but when halftime substitute Pervis Estupinan sent a thunderbolt past Spurs keeper Guglielmo Vicario and Joao Pedro netted a second penalty the game seemed over.
However, when Tottenham's late substitute Alejo Veliz fired home from close range in the 75th minute and Ben Davies scored with a header a miraculous comeback suddenly looked possible.
Midfielder Pierre-Emile Hojbjerg hit the post for Spurs in stoppage time as Brighton looked nervy but they held on to move into eighth place in the table on 30 points while Tottenham remain fifth on 36, a point behind Manchester City in fourth.
Reuters
