The question is, if this goes the distance, does Lopez being on top in the early rounds carry him?

Warrington is a little quietened here, both men are tired but the Leeds Warrior has taken some serious body blows and they could be hampering him.

The Leeds crowd attempting to rouse their man, but Lopez is taking the centre of the ring more regularly.

That was his round.

Warrington told his corner at the last break that he has been hurt to the body. We shall see if that has an impact.

Oof, a good right from Warrington clearly hurt Lopez, bending him double. The Mexican is looking for hold for the first time.

The crowd were quietened a tad in the opening rounds but they have found their voice again now their man is getting on top.

Half-way point, how are we calling this?

Thumbs up for Warrington, thumbs down for Lopez.

I'd be quite surprised if this did not go the distance. Two fighters evenly matched in style and power.

Lopez hasn't stopped smiling, chattering at Warrington, trying to unsettle him... but then a huge left hook from Warrington!

That was the best punch of the fight so far, but Lopez just grinned it off.

I think Warrington is in the ascendency though.

Image source, Mark Robinson

Carl Froch
Former world super-middleweight champion on BBC Radio 5 Live Sport Extra

Lopez swaggered back to his corner but unfortunately he's being outworked.

Lopez has an awkward unorthodox style but there isn't enough substance to it. He's not landed effective shots.

Warrington is making it rough and rugged and I think he'll be impressing the judges.

For the first time there, Warrington had a round where he was clearly on top.

This is Lopez's title bout debut, remember, while Warrington has been to this rodeo many times.

A little needle between the fighters for the first time at the end of the last round, referee Bob Williams swiftly cutting it out.

A reminder now that we have had four rounds, if Williams calls it off for Lopez's cut, we get a result via scorecard.

The frenetic energy of the opening rounds has tapered now, but still some good shots coming in. A few more from Warrington, who seems to have worked out his front-foot approach was playing into Lopez's hands.

Barry Jones
Former world champion on BBC Radio 5 Live Sport Extra

Lopez is so hard to read, you can't read his rhythm. He started fast in that round and then took his foot off the gas.

Josh needs to more direct with his punches, stronger, straighter shots.

Lopez's cut has been well treated by his corner, and the Mexican seems unfazed.

Warrington is struggling to bring his usual intensity here, and Lopez is smiling, smirking his way through this fight. He is right at home in his first title bout.

A couple of good shots from Warrington there though, including one to Lopez's elbow.

This is a really good contest.

Image source, Mark Robinson

Barry Jones
Former world champion on BBC Radio 5 Live Sport Extra

I thought Lopez finished strongly but Warrington was neater.

Warrington has his hands nice and high with his elbows tucked in tight. I felt Warrington was more effective in that round.

Warrington more circumspect now, watching Lopez for the openings. He finds one, but the Mexican responds. Tit for tat.

Lopez finding a few body shots, it was with those that he carried his win over Isaac Lowe.

So far, Lopez has come into Warrington's house and is causing quite a stir.

Carl Froch
Former world super-middleweight champion on BBC Radio 5 Live Sport Extra

It was an accidental clash of heads. The referee hasn't penalised Warrington because it wasn't intentional.

Warrington comes forward in straight lines and that is going to happen. Lopez just has to suck it up now.

We need four completed rounds before a contest stopped for a cut goes to the scorecards - anything prior would be a no-contest, like Warrington v Lara II.

For now, we continue.

Image source, Getty Images

Ouch! The replays show that clash of heads and it was a bad one - Lopez took a real whack.

He's getting plenty of treatment to that cut near his left eye.

Image source, Mark Robinson

Wasn't intentional from Warrington, but a reminder that his second fight with Maurizio Lara was called off early after Lara was cut in a clash of heads.

Hopefully we won't have another early night.

Warrington is still firing out the jabs, but everything is being countered by Lopez.

Some big hooping air shots by Lopez, but when he hits you feel it.

There are gaps for Warrington, but he hasn't taken advantage yet.

Ooh, Lopez has been cut on the left eye! Warrington caught him with the head it seems.