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

"Cahill has got away with one there. He needs to be careful."

Chelsea are feeling the pressure here a bit. Thibaut Courtois just sliced a routine clearance straight out of play.

Moments before, Gary Cahill ran the risk of a second yellow card when he tangled with Lee Cattermole. Fortunately for him, referee Mike Jones decided a stern word would suffice.

That goal has got the home crowd going, hardly surprisingly. 

Sunderland are on the front foot here, and they have got three minutes of stoppage time at the end of the first half to make it count.

Jason Roberts
Former West Brom striker on Final Score

"It has flown into the top corner. I think Sunderland have been credible, always creating chances."

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

"That comes out of absolutely nowhere. The angle is incredible. 99 times out of 100 that does not land in the back of the net. 

"What a hit you will not see many better this weekend."

Image source, Rex Features

For all their hard work going forward, Sunderland cannot afford to be as sloppy as this at the back if they want to get back in the game.

The Black Cats defence stops after they think Diego Costa has run the ball out of play after beating the offside trap, but play continues and Cesar Azpilicueta almost takes advantage, nipping in and rippling the side-netting with an opportunistic strike from a tight angle.

Sunderland are only down to 10 men for a matter of seconds before Fabio Borini is waved back on, and he joins their latest attack. They have plenty of men forward for this one, but very little room inside the Chelsea area and the threat ends when Jan Kirchhoff's shot from distance is deflected on its way through to Thibaut Courtois.

Borini is back on his feet but looks a little groggy to say the least. He is going off for more treatment. John Terry is able to continue.

John Terry goes for another header, and ends up injuring himself and Sunderland forward Fabio Borini, who got caught by Terry on the side of the head. Terry is up on his feet, Borini is still on the floor.

Chelsea look in complete control at the back and then this happens - John Terry's poor header lets in Sunderland down the left and Jermain Defoe almost get on the end of the resulting cross.

Sunderland stay on the attack, and Lee Cattemole slips Defoe clear... but the flag is up again and this time replays show it is clear cut - Defoe was a yard offside.

It's been all Sunderland in the last few minutes but here come Chelsea. Branislav Ivanovic fires in a fizzing low cross from the right, which only eludes Diego Costa's outstretched boot by inches.

Sunderland are still putting the effort in. This time they do get the ball into the Chelsea area and Deandre Yedlin hurls himself at the ball at the far post, but his header is under pressure, straight at Thibaut Courtois and lacks power in any case.

As if to neatly illustrate (at least half of) my last point, Sunderland work the ball forward well but run out of ideas outside the Chelsea box and Yann M'Vila blasts a hopeful shot well off target.

Sunderland are putting in an incredible effort but Chelsea look well organised at the back, and are dangerous on the break. It is going to be tough for the Black Cats to get back into this.

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

"It is an incredibly open game which makes it even more nerve-jangling for the Sunderland fans."

Dion Dublin
Former Leicester and Aston Villa forward on Final Score

"Chelsea got lucky. They tried to play a one-two through the Sunderland defence but the ball ricocheted and fell to the feet of Diego Costa. The right man at the right time, and he just curled it round the keeper. Chelsea have so much quality.

"That's so deflating for Sunderland, who had been playing well for 15 minutes."

Sunderland have not  done much since falling behind but they go close here, with Jermain Defoe getting behind the Chelsea defence and nodding Lee Cattermole's hoisted ball against the post. The linesman's flag was up, so it would not have counted, but replays show that was a very tight call indeed.

A bit of encouragement for the Black Cats, and they need it...

Chelsea are bossing things at the moment. Sunderland are not just a goal down, they are chasing shadows.

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

"Chelsea were a little bit lucky in the build-up play but they had the ball for a good period. It dropped perfectly to Diego Costa and he never looked like missing.

"That is a tough one to take for Sunderland because they started so well."