Tottenham Hotspur's hopes of winning this season's English Premier League title suffered a potentially fatal blow on Friday when they were beaten 1-0 at West Ham, dpa reported. Manuel Lanzini smashed in the only goal midway through the second half to leave second-placed Tottenham still four points behind Chelsea, having played a game more. Tottenham manager Mauricio Pochettino denied the title race was over but admitted catching Chelsea would "be difficult, with three games to play." "You have to try to give your best. Now we move forward," he said. "It is not over. It is true that it will be difficult. Now we have to wait." Chelsea will win the title if they win their next two games, starting with Monday's encounter with Middlesbrough at Stamford Bridge. West Ham climbed to ninth on the table with their win on Friday. Tottenham went into the match after nine wins in a row but West Ham proved obstinate opponents, producing perhaps their best performance of the season. Harry Kane had a couple of chances to put Tottenham in front in the first half but West Ham held out until half-time and snatched the vital goal on 65 minutes.