Anthony Joshua and Andy Ruiz Jr are in Saudi Arabia and both fighters are in their final preparations for the huge rematch this weekend.
Joshua, 30, seeks to reclaim his WBA, IBF and WBO world titles following his surprise seventh round loss to Ruiz in New York last June.
Diriyah Arena, Riyadh, Saudi Arabia
Andy Ruiz Jr v Anthony Joshua (WBA, IBF and WBO world heavyweight titles) - ring walks expected at 21:00 GMT
Dillian Whyte v Mariusz Wach (non-title heavyweight fight)
Alexander Povetkin v Michael Hunter (WBA world heavyweight title eliminator)
Filip Hrgovic v Eric Molina (WBC international heavyweight title)
Mahammadrasul Majidov v Tom Little (non-title heavyweight fight)
How can I watch Joshua vs Ruiz 2?
Sky Sports Box Office begin their broadcast from 5pm GMT.
It costs £24.95, with the full undercard and main event shown.
You can also live stream for the same price on your computer, mobile and tablet devices.
Sky Sports Boxing Facebook and YouTube channels will show an hour of build-up - including Majidov vs Little - for free from 4pm.
What will the fighters earn?
Joshua, despite being the challenger, is reportedly earning £66m for the Clash on Dunes. It's the biggest payday a British boxer has ever received. The champion Ruiz Jr is said to be earning £10m for the rematch.
What are their records?
Anthony Joshua has lost once in 23 fights, winning 22. 21 by KO.
Andy Ruiz Jr has won 33 from 34. His one loss was in a title fight to Joseph Parker. 22 of those wins have been by KO.
What the fighters said?
Andy Ruiz Jr: “I’m confident about the rematch, but I don’t underestimate any fighter. I know AJ’s going to come stronger and more focused but inside the gym, like Mike Tyson says, everyone has a plan until they get hit.
“I’m sure everybody was trying to look for an excuse and reason why he didn’t perform and why he lost. I think it was down to the style. Styles make fights and I’ve been calling AJ out for a while. I knew his style was perfect for me and that’s why I plan to do the same thing.”
Anthony Joshua: "I'm punching loose and heavy - rhythm and flow. Before I was trying to bench-press a house. I used my body to get where I needed but then I started realising the sweet science of the sport. I am punching like a horse kicking backwards right now.
"When Muhammad Ali was training he said he would build a shack to train in. There are clues to success and you have to go back to what it takes to be a great heavyweight champion. We had to bring in hard, rough sparring partners. I brought in the toughest and roughest."
I think Joshua will be far more cautious in this contest and he will not want to taste Ruiz's rapid combinations once again. Ruiz is fast, powerful and durable and I expect Joshua to keep the fight at long range and look for a late stoppage.
If Joshua tries to slug it out once again, Ruiz could well triumph as he has quicker hand speed. I'm going for Joshua in 10 or 11...but I'm not totally convinced.