Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"How fitting that Defoe gets the winning goal? 

"He has held this team together. For their second-half attitude and Sam Allardyce’s changes they deserve the three points today - no argument."

The Sunderland players are celebrating, and so are their fans. Their latest Great Escape is on - the Black Cats are out of the bottom three, and have a game in hand on Newcastle, who are immediately below them... one more win and Big Sam's side are safe.

For a developing match report, head here. For all the reaction from Stadium of Light, head here instead.

Vito Mannone springs to his left to keep out a Bertrand Traore shot... and there goes the final whistle!

Chelsea will end the game with 10 men - John Terry gets his second yellow card, for a late lunge on Wahbi Khazri. 

A huge roar from the Sunderland crowd, as their side win a throw-in. They are almost over the line today, at least...

Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"There are no signs of tiredness from Sunderland.

"At the moment it is just mayhem."

Chelsea still have the ball... but Sunderland are very, very grateful to see Bertrand Traore's cross trundle into the arms of Vito Mannone. Black Cats boss Sam Allardyce is so animated, he is almost on the pitch.

Tense, tense times at the Stadium of Light. Chelsea are on the attack, and there will be FIVE minutes of added time.

A delay here while Sunderland wait to take a free-kick and Younes Kaboul is booked for taking too long over it - he argues Cesc Fabregas had not retreated 10 yards, but to no avail.

That's just one of a flurry of bookings by referee Mike Jones - Chelsea's John Terry went into his book for conceding the free-kick in the first place, and then Seb Larsson was shown a yellow card for booting the ball away when Chelsea threatened a quick counter from a throw.

While Sunderland's Wahbi Khazri receives treatment, Chelsea make another change - Bertrand Traore replaces John Mikel Obi.

Chelsea make their second switch - Oscar is on for Willian.

Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"The tactics are so obvious from Sunderland now, nine men along a strip of two yards 18-yards out when Chelsea have the ball."

More Chelsea pressure, but Sunderland hold firm and now it is their turn to threaten on the break.

Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"It is torture, absolute torture for these Sunderland fans."

Sunderland have got some defending to do now, after that flurry of goals. Vito Mannone has to tip  Willian's free-kick over the bar and the Black Cats clear the resulting corner.

Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"Sam Allardyce has been here before. He knows what he is doing."

Gaz in Durham

Pat Nevin
Ex-Chelsea winger at Stadium of Light for BBC Radio 5 live

"They are a totally different side this second half Sunderland. When it falls to Defoe I don't think anyone expected anything else."

Dion Dublin
Former Leicester and Aston Villa forward on Final Score

"The first touch of the ball from Defoe just killed it, and all he had to do was swivel and shoot. There is no-one better in the league at controlling the ball and turning with it. It's what he's at Sunderland to do." 

Image source, Reuters

Chelsea brought on Baba Rahman for Branislav Ivanovic just before that third Sunderland goal. Cesar Azpilicueta is now playing right-back.

The Black Cats have just made their final change, bringing on Seb Larsson for Lee Cattermole.