Cleverly is wedged against the ropes and only the bell saves him after an absolutely barrage from Jack. The nose is bust up, blood everywhere, there is a cut around the eye and Cleverly is in danger of losing his first world title defence. He needs something special to save this one.

The arena is still only a quarter full, which is a pretty sad state of affairs considering the venue only holds 20,000. Jack is producing some of his best work so far, dominating the round and landing at will. Cleverly takes a heavy hook shot to the head. He is in trouble.

Cleverly is throwing a lot of punches, but doesn't seem to be making too much of an impact so far. Jack looks far more efficient, while Cleverly is having a quiet round after burning off a lot of energy in the previous round.

Cunnaye: Badou v Clev should be better than the main event. Exciting! Can't wait for some boxing.

Image source, Getty Images

Luke Reddy
BBC Sport boxing reporter in Las Vegas

The arena just let out its biggest cheer. Why?

Conor McGregor is here. He was filmed walking down a corridor next to girlfriend Dee Devlin, who was pushing Conor Jr in the pram.

Conor Snr's swagger was off the scale. His shoulders swayed as if he was walking in a gale...

Naughty from Jack who sends a punch further south than it should be. But it has still been an encouraging start for the Welshman, who is busy, but maybe not as effective with his punches as he would like to be.

One slight concern for Cleverly would be the amount of energy he is using up so early on.

It is a busy start for the Welshman, who is fighting in arguably the biggest occasion of his career.

Cleverly takes the centre ground in the ring, throwing out left hooks to try to unsettle the Swede.

But Jack shows it is not going to be easy for the current champion with a circling right that gets through the Cleverly guard.

Luke Reddy
BBC Sport boxing reporter in Las Vegas

Image source, ..

Nathan Cleverly walks to the ring, bandana perfectly placed, he's like the Karate Kid.

Very confident swagger, he's nodding and acknowledging the crowd.

Make no mistake, this is a tough, tough ask. The biggest win of his career if he can overcome a durable Mayweather fighter.

Jimmy Lennon Jr tuning up as MC: "fight fans here we goooo..."

It is now time for Nathan Cleverly, who is fighting and trying to defend his WBA light-heavyweight championship, in a practically empty arena.

Hopefully the crowd will take their seats pretty soon or this genuine world title defence will be played out in front of a pretty sorry-looking sparse crowd.

Luke Reddy
BBC Sport boxing reporter in Las Vegas

Image source, .

I spent a bit of time with Nathan Cleverly in midweek. It's safe to say he played along with the hype of tonight's main event, answering questions respectfully. But you could tell he only had focus for his own fixture with the tough Badou Jack.

Cleverly told me he's felt the lows of boxing on times in recent years but he's back now. Interestingly he opts to only use one coach for both his boxing and strength training. It's not the normal approach in an era where world level fighters tend to have broader teams.

Tonight, by his own admission would be the biggest win of his life.

Nathan Cleverly has warned his opponent Badou Jack about the risks of stepping up in a weight class.

The WBA light-heavyweight champion had a short campaign himself at cruiserweight before dropping back down to win his second world title.

And Cleverly says his experience at this level will be a key factor.

"I think he may feel stronger at the weight, and feel as though he has more energy," he told BBC Sport.

"That extra bit of weight can invigorate you. He may be more confident and stronger. But I'm established at this weight for years and at some point in the fight you will see that difference."

Image source, Getty Images

Some quotes from Nathan Cleverly before his WBA light-heavyweight defence against Badou Jack.

"This moment has soon come around and we're ready," the Welshman told Sky Sports.

"This is the most important bit, so let's execute it in the best fashion.

"I'm predicting a long-distance fight, I think it's going all the way, but I'm going to win this on a unanimous decision."

Welshman Nathan Cleverly is next up in his eighth world title fight against Sweden's Badou Jack.

Cleverly is a two-time champion at light-heavyweight after previously holding the WBO belt and is now the proud owner of the WBA version with a stoppage win over Juergen Braehmer last year.

Jack is the former WBC world super-middleweight champion and has previously fought Britain's James DeGale and George Groves.

The 33-year-old gave up his title so he could step up and face Cleverly in his first light-heavyweight fight.

And former Chelsea and Germany footballer Michael Ballack is another keen watcher.

Luke Reddy
BBC Sport boxing reporter in Las Vegas

Ozzy Osbourne is in the house. He's just rolled in with Sharon and son Jack. They've made their way to the posh seats.

With a big Vegas fight comes the glitz and glamour from various A-list celebrities.

One Direction singer Niall Horan has already shown his support for McGregor.

A select number of the world's elite with unlimited cash flow will be ringside for this event including musicians Drake and Adam Levine, actresses Charlize Theron and Angelina Jolie, basketball star Lebron James and even the mighty Thor, also known as Chris Hemsworth.

And, in more celebrity news...

Footballer turned Hollywood star Vinnie Jones is among the crowd at the T-Mobile Arena. He says McGregor needs to finish things early if he is to be victorious.

BBC Sport app users may need to click on the link to see the tweet.

I said Mayweather was looking relaxed. Television footage has just shown him getting a massage backstage. He looks like he is at a spa instead of preparing to try to not get hit in the face by a very angry Irishman.

Luke Reddy
BBC Sport boxing reporter in Las Vegas

Image source, .

Meet Colman Gogan, from south Florida.

Another American supporting The Notorious. He assures me he has Irish blood through his dad. The dungarees are all I need really, to me he's as Irish as a Shamrock.

He tells me McGregor will win but I sense doubt. That's been common this week, people backing the UFC man but giving off an air of hope rather than conviction.