There will never be much sympathy on derby day and Marc Cucurella’s slip was ruthlessly punished, as Brennan Johnson raced forward to provide a cross that Dominic Solanke met ahead of Levi Colwill and turned into the net.
Cucurella slipped a second time inside 11 minutes and Chelsea were made to pay again, with Dejan Kulusevski guiding a strike inside Robert Sanchez’s post.
The left-back ran off to change his boots while the hosts rejoiced, but the celebrations were soon quietened as Cristian Romero was forced off a quarter-hour into his return from injury before Jadon Sancho glided inside and fired a brilliant effort in off the post.
Cole Palmer uncharacteristically passed up an opportunity to equalise before Son Heung-min came agonisingly close to picking out the top corner at the other end.
Fraser Forster then got down brilliantly twice in quick succession to deny Palmer and Pedro Neto, while Pape Matar Sarr headed onto the crossbar and Solanke couldn’t get a convincing contact on Son’s fizzed ball at the other end.
With the game only slowing down when Spurs fans threw objects onto the pitch, Radu Dragușin made a vital block to deny Nicolas Jackson shortly before the break.
The Blues came out defiantly for the restart looking to draw level, as Sancho linked up with Cucurella but was denied by Forster before Enzo Fernández curled his strike agonisingly past the post.
There was more injury concern for Spurs as Johnson trudged off and there was more misery on the way too when Yves Bissouma recklessly flew into a sliding tackle on Moises Caicedo to concede a penalty, which Palmer clinically converted to equalise with half an hour remaining.
Son then missed a golden opportunity after there was confusion over an offside call and Micky van de Ven headed wide as Spurs fought to regain their lead.
It was Chelsea who went ahead, though as Palmer danced into the box and hit a pass that deflected into Fernandez’s path for the midfielder to smash it home.
There was more pain for the hosts with Van de Ven going off before Sarr brought Palmer down for another penalty, with the Blues’ talisman rubbing it in with an audacious Panenka as Spurs suffered back-to-back defeats despite Son’s late goal.
They now sit nine places below Chelsea, who are second in the table having extended their unbeaten streak to eight matches across all competitions.