Chemsdine Talbi scored in second-half stoppage-time to propel Sunderland to a 2-1 comeback victory over Chelsea and lift them to second in the Premier League.
The Black Cats substitute snatched all three points in the third minute of stoppage time at Stamford Bridge, where Wilson Isidor had cancelled out Alejandro Garnacho’s early effort.
Garnacho fired the Blues in front with his first goal for the club, and the quickest scored by Enzo Maresca’s side in the top flight this season.
Yet Chelsea were pegged back by Isidor’s fourth league goal of the campaign, and after withstanding what their hosts could throw at them in the second half, Sunderland sealed a memorable triumph thanks to Talbi’s neat first-time finish.
Sunderland are now on 17 points, just two behind leaders Arsenal, with Chelsea three points back in seventh place.
How the match unfolded
Sunderland made a bright start, with Dan Ballard afforded a free header that he nodded straight at Robert Sanchez after just 56 seconds.
But it was Chelsea who struck first in the fourth minute. A turnover in midfield led to Pedro Neto quickly switching the play to Garnacho, who drilled through Robin Roefs' legs from a tight angle.
But Sunderland pulled level 18 minutes later when, from Nordi Mukiele's long throw, Bertrand Traore's shot ricocheted into the path of Isidor, who bundled home from close range.
With Roefs making saves to deny Garnacho and Trevoh Chalobah before the break, Chelsea kept up the pressure after half-time, yet despite enjoying large spells of possession, they lacked a cutting edge in front of goal.
And that proved costly when Brian Brobbey brilliantly held the ball up before laying it off for fellow substitute Talbi, whose cool, low finish into the bottom-right corner sent the travelling Sunderland supporters behind the goal into raptures.
Blues stunned at the death
Chelsea not only saw their four-match winning streak in all competitions brought to an abrupt end, they also missed the chance to apply some pressure to leaders Arsenal.
Ballard's header inside the opening minute served as an early warning for Maresca's side that the visitors were not going to roll over.
Nevertheless, all seemed on track when Garnacho broke the deadlock soon after.
However, the tables turned as Chelsea were undone by Mukiele's long throw, with Isidor taking full advantage of the ensuing chaos to cancel out their lead.
Despite the setback, Chelsea carried the greater attacking threat thereon, and it took smart reflex saves from Roefs to thwart Garnacho from close range and then Chalobah from distance.
However, the game’s third goal eluded them and they were stunned following a devastating stoppage-time counter, with Talbi’s lovely finish silencing the Stamford Bridge faithful, whose team had been on the end of a last-gasp winner in their previous home league outing, against Liverpool.
Maresca’s side will look to bounce back against Wolverhampton Wanderers in the EFL Cup in midweek, before travelling across London to face Tottenham Hotspur on Saturday, but the Italian will know that this kind of result could be what costs Chelsea in their desire to really push on in a title challenge.
Sunderland’s capital gains
By any measure, it has been a fantastic start to the season for Sunderland on their return to the big time, and this result tops the lot.
Their tally of 17 points is their joint-best after their opening nine games in a Premier League campaign. Plus, the Black Cats are also now unbeaten in each of their last 14 league matches in London.
Sunderland’s confidence was epitomised by their purposeful start, and they were unfortunate to find themselves behind to Garnacho’s smart finish.
They responded well, though. Enzo Le Fee sent a free-kick narrowly over soon after, before another set-piece led to their equaliser, with leading scorer Isidor in the right place at the right time once again.
After that, it was largely backs to the wall for the visitors, but, they dug deep and their efforts were rewarded in dramatic fashion.
Terrific centre-forward play from Brobbey was integral. The former Ajax striker showed great strength to hold off his markers and then find the onrushing Talbi, who still had plenty to do with his finish.
Regis Le Bris’ side will be desperate to continue this momentum heading into the next international break, with back-to-back home games coming up, first against Everton next Monday, and then Arsenal.
Surely, not even the boldest of Sunderland fans would have thought that an encounter against the Gunners would be a potential top-of-the-table clash, but that is the state of play as it stands.
Club reports
Chelsea report | Sunderland report
What the managers said
Enzo Maresca: "We started well with the ball but we were losing the second balls and against these sort of teams you have to know how to deal with that. Overall, we were not good enough.
"It was not one of our best performances. You can drop points against any team if you do not perform at 100%."
Regis Le Bris: "We tried our best to design a game plan for this game. I think it worked well even if we conceded an early goal. High press, they have this ability to exploit space with their players going one v one. Their players have many offensive threats so they scored early. With the ball we were alright I think. Without the ball it was tough but it got a bit better.
"The second half was really good. It didn't feel like it was possible for them to score. We felt the momentum shift a bit and it was possible to score."
Next PL fixtures
Key facts
Sunderland’s 17 points from their opening nine Premier League games is the best return by a promoted club at this stage since Hull City in 2008/09 (20).
Chelsea have dropped six points from winning positions in Premier League home games this season, the most of any side.
Talbi scored Sunderland’s third-ever 90th-minute winning goal in a Premier League away game
Sunderland are unbeaten in their last 14 away league games in London (W5 D9), extending their longest ever unbeaten run in the capital.