Oscar De La Hoya is backing Manny Pacquiao to upset the odds in Las Vegas and hand Floyd Mayweather the first defeat of his professional career.

De La Hoya believes Pacquaio’s aggressive attacking style could cause problems for the American in their May 2 super fight.

However, the former six-weight champion, has warned the appointment of referee Kenny Bayless has already handed Mayweather an advantage.

De La Hoya is well placed to give his opinion on the two fighters after sharing a ring with both during his glittering career.

‘The Golden Boy’ lost a split decision to Mayweather in 2007 and then 19 months later was battered into retirement by the Filipino super star following eight brutal rounds.

De La Hoya, who is currently at a celebrity golf event in Dubai, told thenational.ae: “I feel Pacquiao has to win the first two or three rounds, because it’ll make Mayweather have to come from behind and he’ll have to start to pressure Pacquiao, to be the aggressor, and Mayweather does not like to be the aggressor.

“So if Pacquiao can start well the first two rounds – winning those rounds – the fight can go in Pacquiao’s direction.

“The one fighter to make it an exciting fight is going to be Pacquiao. What he has to do is go in with a lot of combinations, a lot of footwork, which he has. And I hear he’s in tremendous, tremendous shape.

“With Mayweather, we’re going to see the same thing he does in every fight, which is box, win the rounds one at a time. I don’t see Mayweather trying to knock out Pacquiao, but I can see Pacquiao trying to knock out Mayweather. In this sport one punch can change everything and I think I’m going to have to give Pacquiao the advantage.”

De La Hoya, however, has questioned the appointment of veteran official Bayless, who has been the third man in the ring for five of Mayweather’s fights and seven of Pacquaio’s.

“History shows that Kenny Bayless protects Mayweather,” added De La Hoya. “Pacquiao is now up against two guys in the ring instead of one. So I would have to say that Pacquiao is already one point behind and the fight hasn’t even started.

“It’s surprising to me, given the history. But it’s Vegas and it’s Mayweather’s home town and they’re going to obviously do what’s best for him.”

Book Mayweather v Pacquiao, Sky Sports Box Office, May 2, via your phone or online now. If you want to record the event, book via your Sky remote from April 25. skysports.com/maypac