West Ham United stunned Chelsea, the leaders of the English Premier League, and beat them 3-2 on Saturday, after they came from behind twice and grabbed the three points with a late goal from substitute defender Arthur Masuako.
Chelsea seemed to tighten their grip on the match after 28 minutes when Thiago Silva headed a corner kick by Mason Mount, and goalkeeper Lukasz Fabianski could only touch the ball before it entered the net.
But the European champions allowed the hosts to return to the atmosphere of the meeting in the 40th minute when Jorginho put goalkeeper Edouard Mendy under pressure with a bad pass back and hindered Senegalese goalkeeper Jarrod Bowen, so that West Ham won a penalty kick by Manuel Lanzini.
It took Chelsea only 4 minutes to regain its supremacy through Mount, who returned to his level after an absence due to problems with his wisdom teeth, as a long pass from Hakim Ziyech reached him with a perfect shot to Fabiansky's net at the near post.
Chelsea included striker Romelu Lukaku at the start of the second half, instead of injured Kai Haverts.
But West Ham equalized again in the 56th minute when Bowen hit a powerful low ball from the edge of the penalty area.
Maswako turned the game in favor of West Ham in the 87th minute when he deceived Mendy with a shot that looked like a cross pass, but the ball fell into the goal at the near post.
The defeat left coach Thomas Tuchel's team one point ahead of Manchester City, who visit Watford later today, and two points ahead of Liverpool, who faces Wolverhampton Wanderers away.