Birmingham City's much-improved second half display continues, but Jonathan Leko is flagged offside as John Stones senses the danger and steps up just in time.

Manchester City are soon down the other end, Riyad Mahrez plays in Gabriel Jesus who lobs the goalkeeper but the ball is cleared by Mikel San Jose.

Bernardo Silva almost pokes in from the corner, but Andres Prieto is eventually able to gather.

Image source, Reuters

Bielsa makes his final two changes, with Raphinha and Sam Greenwood coming on.

Ian Poveda and Leif Davis are off.

It's been a scrappy start to the second half at Oakwell with neither team really finding their rhythm yet.

Tranmere more than holding their own against their Championship hosts.

Martin Keown
Former Arsenal defender on BBC One

Crawley manager John Yems will know that that this is a big period in the game because Leeds are going to come after them now.

There has to be a reaction.

Image source, Reuters

Wow. Leeds have previous in the FA Cup when it comes to being upset by lower-league opposition, but Marcelo Bielsa's side must be stunned by that quick double for the hosts.

The Premier League side look to hit back through Helder Costa, but he can't stretch a leg out far enough to poke into an empty net.

Ed Foster: Crawley Town are playing so well in this 2nd half. That first goal was an absolute cracker! The Leeds keeper had a mare for the 2nd though. Hope they can hang on.

Andy Walsh: It’s funny how the media’s Bielsa love in changed when Leeds start losing

It remains level in this one thanks to Callum Johnson's effort before the break.

Martin Keown
Former Arsenal defender on BBC One

Well, well, well.

This is unbelievable!

Image source, Getty Images

Mark Schwarzer
Former Middlesbrough & Fulham keeper on BBC TV

It's another really good ball into the box from Hakim Ziyech - every time he gets on the ball he is looking to do something with it.

Callum Hudson-Odoi times his run well but I thought his first touch had lost the opportunity but he does really well to pivot and strike. It's too strong a strike for the keeper to prevent it going in.

A really good goal.

A positive start to the second half for Birmingham City, who are able to put together some passes around the edge of the Manchester City penalty area before the move breaks down.

John Stones then beats Jonathan Leko to a ball down the right as the visitors come again. Much better by the Championship side.

Chelsea beginning to purr in the final third.

Hakim Ziyech finds a bit of room once again and goes for the top corner. It floats over the bar but it looks like they're enjoying themselves now.

Changes for both sides for the second half.

John Stones, Felix Nmecha and Taylor Harwood-Bellis are on for Manchester City, in place of Ruben Dias, Kevin de Bruyne and Joao Cancelo.

Marc Roberts and Adam Clayton come in for Birmingham City.

Pablo Hernandez strides on to a cut back on the edge of the Crawley box but curls his effort high and wide. He looks suitably glum afterwards, too.

Jack Whatmough is on for Portsmouth in place of Rasmus Nicolaisen, who had been booked.

Luke Thomas trots on to replace Dominik Frieser.

We're back under way!