Luka Milivojevic joins Palace team-mate Christian Benteke in the book, after impeding Willian. It is Willian who takes the resulting free-kick, but cannot keep his shot down.

Another Palace free-kick, another Palace chance. This time Damien Delaney meets Yohan Cabaye's delivery at the back post and heads it back towards Christian Benteke, who cannot quite make proper contact under pressure... and the ball loops high and wide.

Chelsea have put in 21 crosses from open play today, but not many of them have found a blue shirt. Palace continue to defend doggedly when the home side come forward, and always seem to have a man in the right place to head clear.

Palace striker Christian Benteke cleans out Gary Cahill after chasing him down by the left-hand touchline. That looks like a booking... and it is.

Speaking of which, Palace midfielder Yohan Cabaye bends in a wicked free-kick from the left. Nobody gets on the end of it, but it bounces only a yard or two wide.

Willian has taken over from Pedro in the right wing-back role for Chelsea and is already making an impact, flinging in a couple of dangerous crosses. 

Palace clear them both, but this is going to be a long 25 minutes or so for Sam Allardyce's men... unless they do nick a third of course.

Chelsea need an equaliser, as you know. Instead they are almost 3-1 down - how important will this save by Thibaut Courtois prove to be?

When play resumes, Palace break clear and Wilfried Zaha charges in on goal... only to see Courtois throw out a leg to divert his shot around the post.

Scott Dann is being carried off, to be replaced by Damien Delaney. Martin Kelly is also on, for Andros Townsend, and I think they are going to play with three centre-halves.

Chelsea have also made a change - Willian is on for Nemanja Matic.

Looking at the replays, Diego Costa accidentally caught Scott Dann with his follow-through after swiveling to shoot. The Palace defender twisted something - his ankle - I think as he went down too.

Palace are hanging on for dear life here... Pedro finds Diego Costa with a peach of a cross, but Scott Dann throws his body in the way of Costa's shot and injures himself in the process. It does not look good for the Palace defender, who has only been on since the start of the second half.

Another Chelsea chance, but Wayne Hennessey makes another key intervention... this time he races off his line to block as Diego Costa stretches for a loose ball inside the box. If not for the Palace keeper, Costa was the favourite to put that one away.

Palace striker Christian Benteke takes on half the Chelsea team on his own but loses out, and here come the home side. 

Diego Costa races clear and checks back to create more space, but his shot is blocked, and Palace survive again.

Diego Costa catches Mamadou Sakho late after lunging for the ball. A first booking of the afternoon by referee Craig Pawson.  

Cesc Fabregas has pushed up alongside Diego Costa as Chelsea probe for weaknesses.

They have not found any yet - Eden Hazard got in a cross that found Diego Costa at the back post but he was back-pedalling to reach it, and could not generate any power with his header, that Wayne Hennessey collects.

Palace get the second half started. They have made a change at the break - James Tomkins is injured so Scott Dann is on instead.

It's been an excellent first 45 minutes in the west London sunshine.

Leaders Chelsea made the perfect start... but Palace quickly replied - twice - and Wayne Hennessey has protected their lead brilliantly since then.

There will be two minutes of added time at the end of the first half. Chelsea have had eight efforts on target so far, but they are behind to Palace, who have scored with both of theirs.

It is Chelsea who are ending this half on the attack, though. Cesar Azpilicueta's powerful strike flashes over, before Wayne Hennessey has to tip over a Nemanja Matic header from a free-kick.

Some respite for Palace... and almost more than that. Andros Townsend sends over a deep corner from the right and James Tomkins is allowed to meet it at the back post. He heads back across goal, and also over the bar... but the ball flicks the roof of the net on its way down - that wasn't far away.

As soon as I write that, Chelsea find a way through.

First Marcos Alonso finds space down the left of the Palace area and fizzes in a low cross-shot that Wayne Hennessey gets something on to stop a Blue shirt from reaching it.

Then Eden Hazard bursts into the box down the right, but Hennessey blocks his shot at his near post... and then the Palace keeper gets down well to push away Nemanja Matic's low effort from distance.