Tottenham's 28-year winless run at Chelsea ended in spectacular style as Dele Alli struck twice in a 3-1 victory at Stamford Bridge.
The result leaves fifth-place Chelsea eight points off the final remaining Champions League qualifying spot and raises added questions over Antonio Conte's future as boss.
Alvaro Morata capitalised on Hugo Lloris' error to nod Chelsea in front on 30 minutes before Christian Eriksen's wonder strike from long distance levelled things up just before the break. Alli then brilliantly controlled Eric Dier's long ball and put Tottenham ahead just after the hour mark and conceded another soon after.
Tottenham snapped their winless run at Chelsea and continued their unbeaten start to 2018, with Mauricio Pochettino's men now just two points behind Liverpool in third.
Despite their pitiful record at Stamford Bridge and with Harry Kane only fit enough for a place on the bench, Spurs began brightly, with Alli going close following Eriksen's cross after 10 minutes.
Chelsea were next to intimidate when Eden Hazard's dangerous run found Willian, whose deflected effort was palmed away by Lloris. The Frenchman was then beaten by Marcos Alonso, but the Spaniard was correctly ruled offside.
The hosts took the lead when Victor Moses' cross was nodded in by Morata, who made the most of Lloris' suspect positioning and failure to catch the ball.
Willy Caballero, in for the injured Thibaut Courtois, then had to rush out to block Eriksen's route to goal, but he had no remedy to Dane's dipping strike a minute before halftime.
There appeared little danger when Eriksen gathered the ball around 25 yards out but he unleashed a thunderous, swerving effort that left Caballero trapped.
Chelsea's stand-in keeper was then at his best on the hour mark, diving to his right to tip Son Heung-Min's curling effort around the post.
He could do nothing to stop Alli a minute later, though, with the Tottenham man superbly controlling a long ball and finishing off the post for his 35th goal on his 100th appearance in the Premier League.
Alli did not have to wait long for his 36th top-flight goal as he ultimately slid the ball home after Caballero had initially denied Son.
There was more good news for Tottenham on 73 minutes when Kane was introduced three weeks after suffering ankle ligament damage at Bournemouth.
But there was no such delight for Chelsea and Conte, who have now lost five times in their last seven league matches.
