Having made their best eight-game start to a PL season since 1999/2000, Sunderland were dreaming of going second in the table, but those aspirations were dealt a swift blow after just four minutes.
Hitting the Black Cats on the counter-attack, Pedro Neto picked out Alejandro Garnacho, who raced down the left before pulling the trigger to drill a low strike through Robin Roefs’ legs, marking his first goal for Chelsea.
The visitors eventually restored their composure, and after a long throw caused havoc in the Blues’ area, Sunderland were back on level terms as Wilson Isidor reacted first to flick the ball past Robert Sanchez from close range.
Firmly in the contest, a passage of neat play nearly saw the scoreline turned on its head, only for Isidor to fire his effort the wrong side of the post.
Fortunately for the home fans, Chelsea wrestled back control of the game towards the end of the first period, coming close to retaking the lead through Garnacho, whose back-post shot on the slide was scrambled away by Roefs, shortly before Trevoh Chalobah rifled a long-range effort over the bar via a vital touch from the goalkeeper.
Perhaps frustrated with the state of the match as the hour mark approached, Enzo Maresca turned to his bench, introducing Estêvão for goalscorer Garnacho, and just moments after coming on, the Brazilian hammered a deflected shot just wide to lift the Stamford Bridge crowd.
Playing a back five for the first time this season, Régis Le Bris’ men remained organised in the second period, restricting Chelsea to half-chances as the game reached its final stages.
Incredibly, they got the ultimate reward as substitute Brian Brobbey held the ball up and laid off for Chemsdine Talbi to sweep home the winning goal in stoppage time.
A dramatic win here means Sunderland are now undefeated in 14 away league outings against London sides (W5, D9).
As for Chelsea, a disappointing result sees them drop to seventh in the table, three points behind high-flying Sunderland in second.
Flashscore Man of the Match: Robin Roefs (Sunderland)
Key stats
- Chelsea have conceded 5 goals in the last 15 minutes of the second half; only Nottingham Forest (7) have conceded more in the Premier League this season
- Sunderland have scored 3 goals via substitutes in the Premier League this season; only Brighton (5) have scored more
- Wilson Isidor has scored his fourth goal of the Premier League this season, more than any other Sunderland player