Tottenham ended Chelsea's attempt to make Premier League history with a 14th successive victory as the title pacesetters were well beaten at White Hart Lane.
Spurs moved up to third place as headers from Dele Alli either side of half-time made the difference to leave Chelsea five points ahead of Liverpool in second place.
Alli rose to meet Christian Eriksen's cross in first-half stoppage time and the same pair combined to put the game out of Chelsea's reach in the 54th minute.
Eden Hazard had Chelsea's two best chances in each half but Spurs closed out the victory in comfort to put north London rivals Arsenal out of the top four and leave themselves seven points off the top after their fifth successive league win.
Tottenham's season was at a tipping point after a disappointing Champions League exit at the group stage and the poor performance in defeat at Manchester United in early December - but they have responded magnificently.
Mauricio Pochettino's side are gathering impressive momentum, illustrated by the manner in which they overcame a Chelsea side that was starting to carry an air of impregnability.
-BBC