Full-time: West Ham United 2-1 Chelsea
- Cheikhou Kouyate opened the scoring for the hosts with pin-point header.
- Fernandes doubled the Hammers' lead with well struck effort from distance early in the second half.
- Gary Cahill scored a consolation goal with the last kick of the game.
- Fights appeared to break out in the crowd in the final few minutes at the London Stadium.
- Relive the Manchester derby.
Full-time: West Ham United 2-1 Chelsea
All over! A cracking cup tie, that. And the final score was a fair reflection of the game, I feel.
West Ham played some really eye-catching stuff at times and will now be looking forward to the next round. Sadly, I fear the crowd trouble shortly before full-time will distract from their excellence.
Thanks for joining us this evening! Until next time...
GOAL: West Ham United 2-1 Chelsea (Cahill)
Chelsea have one back in the final few seconds - but it's destined to be immaterial. Gary Cahill scores the goal, poking it home from close range.
The trouble in the crowd appears to be escalating, sadly.
Four additional minutes are being played.
And I'm sad to report fights appear to be breaking out behind the West Ham goal. The police are on the scene, trying to calm things down. We'll keep you posted on that.
Another late chance goes begging for the Blues. This time, Willian's dinked free-kick is met by the head of John Terry, but the skipper's effort goes just wide of the post.
Moments later, Hazard goes down under a tackle from Winston Reid, looking for a penalty. His appeals are waved away, though, and the Hammers survive.
Tick-tock, tick-tock... West Ham are within sight of the finishing post, here.
Diego Costa has fluffed Chelsea's best chance of the game!
The Spain international is played through by Willian, but his effort to lift the ball over Randolph dribbles agonisingly wide of the post. That could be Chelsea's last chance of redemption.
Up at the other end now... Payet delivers a delicious cross from the wing, but the returning Ayew can't quite wrap his neck muscles around it. That would have been a memorable return for the striker.
Costa slips in Hazard now, but his strike crashes against the outside of the post and away to safety. This is much, much better from the Blues - but a case of too little, too late? We'll see...
Back-to-back corners now for Chelsea, who are trying to exert some kind of pressure. But their efforts breakdown when Hazard fails to control the ball.
Seconds later, Randolph palms away a cross from the marauding Gary Cahill. One-way stuff for the time being.
Another change for West Ham, with Andre Ayew making his return in place of Lanzini. He gets a warm welcome from the home supporters, who know their side are within touching distance of the next round.
Chelsea have spurned their best opening of the half. Diego Costa leads a break into the Hammers' box and lays the ball back to Willian, but the wideman makes a total hash of it and the ball is dragged across the goal.
The deadlock has been broken at Old Trafford, meanwhile. Want to know who has scored it? See for yourself, eh...
Chelsea are struggling to create anything of note and time is fast running out for them here.
A flat corner from Hazard is backheeled, Gianfranco Zola-style, into the side-netting by Oscar. That would have been a brilliant goal, but it wasn't to be for the Brazilian.
It's all gone a bit flat from a Chelsea viewpoint.
Meanwhile, Fernandes has made way for Sofiane Feghouli for the Hammers. Chelsea are making a switch, too, with Aina being replaced by Pedro. That's all three subs burnt for the away side.
Less than an hour to go and here is the expected change. Hazard comes on for Chalobah. The Belgian has less than 30 minutes to make an impact - but Chelsea are rolling the dice now. Nothing to lose at this stage.
His first involvement in the game sees him fouled by Mark Noble and the West Ham skipper goes into the book.
Time for Eden Hazard, surely? The Belgian was brilliant against Manchester United at the weekend and would offer Chelsea something different.
Time is running out on Chelsea's EFL Cup campaign, as it stands. You need to make some decisions, Mr Conte.
Chelsea don't appear to be as threatening in this second half as they were in the first, to be honest. Their latest attack sees David Luiz overhit a pass for Diego Costa.
West Ham are grabbing this game by the scruff of the neck, with Noble firing wide from distance just now.
A Chelsea change is on the way - and it's not before time, too. Diego Costa comes on for the largely ineffective Michy Batshuayi.
This game might just be done and dusted before Conte turns to his big-name players on the Chelsea bench. I wonder if the Italian regrets not fielding a stronger side tonight, because remember, Chelsea are not playing European football this season.
Anyway, they still have 30-odd minutes to save themselves, so perhaps I'm typing too soon.
GOAL: West Ham United 2-0 Chelsea (Fernandes)
The Hammers double their lead and that could be the match-winner!
Edimilson Fernandes finds the net with a low, accurate effort that creeps into the far corner from just outside the box. The goal came after Begovic made a brilliant last-ditch save to deny Payet, but Chelsea never managed to clear the ball.
Right then, the two teams re-emerge for the second half. Chelsea have 45 minutes to save their bacon in their competition.
We're back under way - hold on to your proverbial hats!
A quick reminder of the Chelsea bench before the second half gets back under way at the London Stadium: Eduardo, Alonso, Matic, Hazard, Pedro, Diego Costa, Solanke
I wonder how long before we see Hazard and Costa?
The game at Old Trafford kicked off at 8pm, by the way, so why not nip over there to see the score? I won't ruin it for you...