Promoted Wolverhampton Wanderers scored three times in the last 18 minutes to record a shock 3-1 victory over Tottenham at Wembley Stadium on Saturday and deal a huge blow to the London club's Premier League title hopes.
Second-placed Tottenham dropped nine points behind Liverpool, who won 5-1 at home to Arsenal, and will be overtaken if Manchester City beat Southampton on Sunday.
Harry Kane scored the opener for Spurs after 22 minutes as the England captain cut inside and unleashed an unstoppable left-foot shot from 25 yards (meters).
Seventh-placed Wolverhampton upped its game after the break and a lengthy spell of pressure was rewarded in the 72nd minute when Willy Boly was left unmarked from Joao Moutinho's corner and powered in a header.
Tottenham, who had won five league games in a row, tried to respond but it was the visitors who finished stronger, going ahead in the 83rd when Raul Jimenez rolled the ball into the bottom corner of the net from the edge of the penalty area.
Wolverhampton made it 3-1 in the 87th when Harry Winks was caught in possession and Helder Costa ran clean through to beat Hugo Lloris.
"We did not dominate the ball in the second half," Tottenham manager Mauricio Pochettino said. "We were wrong in the way we tried to play, too much long ball, and our energy dropped.
"We have had a very good run in the last few weeks and to keep that level is difficult. We are not machines."
Wolverhampton manager Nuno Espirito Santo was delighted with his team's performance.
"We had a lot of belief after the equalizer," he said. "I would have said a draw was a good result, but I cannot control the emotions of the boys if they see space in front of them. To play like this at Wembley — the home of football — is a big thing.
"We have achieved something very special in getting to the Premier League and it has been a very special year."