Main events in Las Vegas don't get much bigger than this weekend when Manny Pacquiao looks to claim one of the only belts that has eluded him throughout his illustrious career. The former eight-division champion from the Philippines will go toe-to-toe on Saturday night with WBA champion Keith Thurman inside the MGM Grand Garden Arena with plenty on the line.

And with this much at stake, oddsmakers have been shifting the line on this fight all week, with Pacquiao now the betting favorite to claim the title. But how do Pacquiao and Thurman's brethren in the boxing community see this bout playing out? Here's a sampling of some of the biggest names in the sport, along with some legends and trainers giving their predictions for Saturday's showdown.

Respect box? Subscribe to our podcast -- State of Combat with Brian Campbell -- where we take an in-depth look at the world of boxing each week, including a complete preview of Pacquiao vs. Thurman at the 44:05 mark below.

Pacquiao wins

Andy Ruiz Jr., unified heavyweight champion

"I'm going with Pacquiao because of his speed and aggressiveness." Pick: Pacquiao UD12 

Shane Mosley, former three-division champion

"I think that Pacquiao is going to win because of the experience, the speed and his power." Pick: Pacquiao UD12

Shawn Porter, WBC welterweight champion

"I'm going with Manny Pacquiao, who still has the hunger, several levels of competitive spirit and quickness out of that southpaw stance that's hard to game plan for. Keith Thurman's young but coming off of a very long layoff and a level of relaxation and comfort that makes it difficult for me to see him being ready for this fight. I don't think Keith's body will be able to withstand what's going to come during those championship rounds. Pacquiao weathers the early storm and wins a decision." Pick: Pacquiao UD12

Mikey Garcia, former four-division champion

"Ultimately, Manny's footwork, hand-speed, combinations and volume punching will carry him throughout the rounds. Keith Thurman has the power to win it, and he's very dangerous for that power, but he's not a better fighter, overall, than Manny. I think Manny takes it." Pick: Pacquiao UD12

Thomas Hearns, former five-division champion

"Manny Pacquiao has the better skills and the experience overall in comparison to Keith Thurman, and I see Manny winning a decision by just out-boxing him." Pick: Pacquiao UD12 

Roberto Duran, former four-division champion

"Manny Pacquiao is very tough and for me, he is going to win this fight." Pick: Pacquiao UD12

Roy Jones Jr., former three-division champion

"I'm going to go with Pacquiao because he's the older and therefore more experienced fighter." Pick: Pacquiao UD12

Gerry Cooney, former heavyweight title contender

Manny Pacquiao's been a phenom, but age has been creeping up on him. Thurman's gonna try to box and use his power, and Manny's been knocked out before. It's a 50-50 fight, but I'm going with Pacquiao, who is really awkward and fast, to win a decision. Pick: Pacquiao UD12

Josesito Lopez, former title challenger and recent Thurman opponent

"In our fight, Keith Thurman took a really hard punch from me that would have taken out almost anyone. That proves a lot about his championship ability to come back to win a fight. Thurman has great power and boxing skills and movement, but I still see Pacquiao pulling out a close decision victory." Pick: Pacquiao SD12

Gary Russell Jr., WBC featherweight champion

"Keith Thurman is probably the bigger, stronger fighter, which will give him the puncher's chance, but I think Manny Pacquiao's work ethic and his punch output will dictate the fight. I really like Keith Thurman, but I don't know which Keith will show up. He has the ability to get Pacquiao outta there, but I see Pacquiao being more consistent. So, I think Manny's gonna outwork him and take it." Pick: Pacquiao UD12

More Pacquiao-Thurman: Complete preview | How to watch | Fighter salaries, prize money

Thurman wins

Deontay Wilder, WBC heavyweight champion

"I like both fighters and what they've been able to achieve. Manny Pacquiao's a legend who still is among the world's best fighters despite his age and having to overcome so many ups and downs. But I'm going with Keith Thurman on a split-decision in this one based on his youth and mentality. People are talking about Keith's last fight against Josesito Lopez, but he feels like he's the best, and that he's not going to let anyone take that away from him." Pick: Thurman SD12

Errol Spence Jr., IBF welterweight champion

"It just depends on which Pacquiao shows up and which Keith shows up. I think Keith will be a lot sharper than he was in his last fight. You know he had a long layoff and is just coming back. Keith is a lot tougher than people think he is. He took a lot of punches in that last fight. He took a lot of punches in the Shawn Porter fight, too. He might be a boxer, but he's tough and he's gritty, so I think he's going to win a split-decision or he's going to blow him out. It just depends on which Pacquiao comes out. If he can turn the tables a little bit and become the Pacquiao of back then, I think he can win. But if it's the Pacquiao that fought Broner, then I think Keith will edge him out and outpoint him. Keith can get on his bicycle and move around and just pot shot him. I think Keith will edge it out." Pick: Thurman SD12

Sugar Ray Leonard, former five-division champion

"Keith Thurman has a ton of talent, power and speed. I like him to win." Pick: Thurman UD12

Leo Santa Cruz, WBA featherweight champion

"I feel that Keith Thurman is going to win because he's younger." Pick: Thurman UD12

Julian Williams, unified junior middleweight champion

"Manny's always super-competitive and I believe we'll see a hungrier and more determined Manny Pacquiao than the one who beat Adrien Broner. Manny may even be able to hurt Keith Thurman as he does everybody, but I believe Keith Thurman will have too much youth for him. Keith may not look great, but I'm going with Keith to win a close decision." Pick: Thurman SD12

Paulie Malignaggi, former two-division champion

"I saw Pacquiao in January beating Adrien Broner who was willing to enter the pocket but not let his hands go. Pacquiao is not a defensive genius, and I'm not saying that he's super hittable. But I do see Keith catching up to him and winning by a late-round TKO." Pick: Thurman TKO11 

Jarrett Hurd, former unified junior middleweight champion

"I believe the youth of Keith Thurman will play a big factor. Yes, Thurman had a long layoff but I think he broke the ring rust after the Josesito Lopez fight." Pick: Thurman UD12

Derrick James, trainer of Errol Spence Jr. and Jermell Charlo

"I think Keith Thurman's gonna beat Manny Pacquiao by a decision as long as he can do what he did for the first seven rounds against Josesito Lopez for 12 rounds against Pacquiao. Keith's consistency will win the fight." Pick: Thurman UD12

Robert Garcia, trainer of Mikey Garcia and Josesito Lopez

"Keith Thurman is strong, solid and smart in the ring, and he has youth on his side, so I see him winning a unanimous decision. I would no doubt pick Manny Pacquiao if this was four or five years ago the way he was dominating, but with him being at the age of 40, that's hard for me to do." Pick: Thurman UD12

Ronnie Shields, trainer of Jermall Charlo and Erislandy Lara

"Keith is fast on his feet and has enough boxing ability to keep Manny at bay. I don't believe a KO will occur. I really believe they both will try for one, but in order for Manny to win, he has to hurt Keith early and often. I don't see it any other way." Pick: Thurman UD12

Too close to call

Tony Harrison, WBC junior middleweight champion

"I have so much love and respect for Manny Pacquiao and Keith Thurman and I've seen fire in each of their eyes. I am envisioning an action-packed, seesaw battle that enhances the legacies of both fighters with the fans getting their money's worth. Manny's been re-awakened into the beast he's been in the past, and when the final bell rings, I believe this fight will end in a draw." Pick: Draw

Stephen Edwards, trainer of Julian Williams

"I can't call this fight. I was picking Keith Thurman due to youth and not being the better fighter. I thought he would control Manny Pacquiao with a check hook. But Thurman has not looked right to me in the training footage. Maybe that's a ploy. Who knows? One fighter is 40 and the other looks rusty. I expect a close and controversial draw." Pick: Draw

Sergey Lipinets, former junior welterweight champion

"The fight looks like a 50-50 proposition. Manny Pacquiao is a way more diverse fighter then Keith Thurman. The big question would still be if Pacquiao has got any of that left or enough to maintain that through 12 rounds. I think we'll see them fight to a draw." Pick: Draw

So who wins Pacquiao vs. Thurman? And which prop bet should you back for a 20-1 payout? Visit SportsLine now to see Peter Kahn's best bets for the July 20 megafight, all from the boxing insider who's nailed three straight Pacquiao and Thurman fights.