Match ends, Sunderland 3, Chelsea 4.
Eden Hazard scored two sublime goals as Chelsea came from behind to win and increase Sunderland's relegation fears.
The Black Cats were ahead through Jozy Altidore's first league goal for the club before Frank Lampard levelled with a close-range header.
Hazard put Chelsea ahead with a curling 20-yard strike, John O'Shea equalising after a scramble before Hazard's powerful finish made it 3-2.
Phil Bardsley's own goal made it 4-2 before he scored at the right end.
It could have been worse for the hosts, Fernando Torres blazing a glorious chance over the bar while O'Shea was fortunate to stay on the pitch after a foul on Demba Ba as the Chelsea substitute was lining up a shot.
The result leaves Sunderland, managed by former Chelsea FA Cup winner Gus Poyet, rooted at the foot of the Premier League table.
Chelsea had arrived at the Stadium of Light with two wins in six games on their Premier League travels, and manager Jose Mourinho bemoaning a lack of consistency from his players.
But the Blues remain second in the table, four points behind leaders Arsenal, after a gritty performance earned a third straight league win.
They did it the hard way, the Blues falling behind for the third successive game after Altidore got the better of John Terry in the 14th minute to lash home from 10 yards.
But unlike Sunday against Southampton, Mourinho did not have to wait almost an hour to see his side respond.
This time Chelsea were on level terms within three minutes, poor defending allowing Lampard to mark his return to the team by nodding Juan Mata's cross into the net unchallenged from six yards.
Sunderland, having started so brightly, were on the back foot.
Torres blazed over when he should have done better before Hazard put the visitors ahead with a delightful finish, the Belgian producing a clever piece of trickery before curling a low 20-yard shot beyond goalkeeper Vito Mannone in the 36th minute.
Sunderland, who had beaten Manchester City and Newcastle in their previous two home games, rallied.
They were level when O'Shea poked home from close range after the visitors had failed to deal with a 50th minute corner.
But Hazard, whose performance was described as "amazing" by Mourinho afterwards, capped a fine individual performance with another tremendous finish after latching on to Lampard's 62nd minute back-pass.
Chelsea went 4-2 ahead when Bardsley turned the ball into his own net in the 84th minute while trying to clear a low centre from Blues substitute Demba Ba.
Bardsley did manage to score at the right end two minutes later, but it was not enough as Chelsea secured an incredible ninth straight Premier League win at Sunderland.
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Sunderland manager Gus Poyet:
"If we can play like this and fight like this and make it so difficult, we will stay in the Premier League for sure.
"Maybe we needed one more corner today, one extra corner in the last six minutes. But we didn't get it.
"It was a great display [by Hazard], probably the best I have seen this season from an individual player."
Chelsea manager Jose Mourinho:
"It was a very good performance.
"Even defensively, I think we did well, but the set-pieces... In the last six minutes of extra time, if they had two more corners, they would have won 5-4.
"When you play so well, you have to win comfortably and not give a headache to the manager in the last six minutes."
- 2BardsleyBooked at 45mins
- 3DossenaBooked at 39mins
- 4Ki Sung-yueng
- 23GiaccheriniSubstituted forJohnsonat 65'minutes
- 8GardnerSubstituted forFletcherat 80'minutes
- 17AltidoreBooked at 90mins
- 14ColbackBooked at 51minsSubstituted forLarssonat 57'minutes
- 10MataSubstituted forMikelat 81'minutes
- 7Santos do NascimentoBooked at 48mins
- 9TorresSubstituted forBaat 65'minutes
- 22WillianBooked at 90minsSubstituted forSchürrleat 90'minutes
- 17E HazardBooked at 62mins
- 15De Bruyne
- Phil Dowd
- Shots on Target
Second Half ends, Sunderland 3, Chelsea 4.
Corner, Chelsea. Conceded by Sebastian Larsson.
Jozy Altidore (Sunderland) is shown the yellow card.
Demba Ba (Chelsea) wins a free kick in the defensive half.
Foul by Fabio Borini (Sunderland).
Attempt missed. Fabio Borini (Sunderland) right footed shot from outside the box misses to the left.
Substitution, Chelsea. Andre Schürrle replaces Willian.
Willian (Chelsea) is shown the yellow card.
Goal! Sunderland 3, Chelsea 4. Phillip Bardsley (Sunderland) left footed shot from very close range to the centre of the goal following a corner.
Corner, Sunderland. Conceded by Frank Lampard.
Foul by Branislav Ivanovic (Chelsea).
Jozy Altidore (Sunderland) wins a free kick on the left wing.
Own Goal by Phillip Bardsley, Sunderland. Sunderland 2, Chelsea 4.
Foul by Demba Ba (Chelsea).
Wes Brown (Sunderland) wins a free kick in the defensive half.
Attempt missed. Ki Sung-Yueng (Sunderland) left footed shot from outside the box is close, but misses to the left.
Substitution, Chelsea. John Obi Mikel replaces Juan Mata.
Substitution, Sunderland. Steven Fletcher replaces Craig Gardner.
Attempt missed. Ramires (Chelsea) right footed shot from the right side of the box is close, but misses to the left.