Arsenal missed the opportunity to regain the top spot in the English Premier League on Thursday after losing 2-0 to its guest and London neighbor, West Ham United, at the Emirates Stadium.
West Ham had only three chances against Arsenal's goal. Still, Tomas Soucek gave them the lead at the end of the first half, before Konstantinos Mavropanos, the former Arsenal player, increased the visitors' lead in the second half.
Arsenal had many good opportunities but failed to score.
West Ham took the lead against the run of play in the 13th minute when Soucek succeeded in scoring after the ball was returned to him by Jarrod Bowen, who appeared to catch it before it left the field.
After that, Arsenal launched several attacks, and Bukayo Saka's attempt hit the post. Gabriel Jesus wasted two good opportunities before Mavropanos scored with a powerful header from a corner kick taken by James Ward-Prowse in the 55th minute.
West Ham could have scored the third goal but Said Benrahma missed a penalty kick in stoppage time after a mistake by former West Ham captain Declan Rice.
Arsenal now has 40 points in second place, two points behind league leaders Liverpool, who won 2-0 over Burnley last Tuesday.