Fight of the Century: Will it be Mayweather or Pacquiao?

The entire sports world will turn its attention to the MGM Grand Garden Arena in Las Vegas where boxing’s biggest fighters of their era, Manny Pacquiao and Floyd Mayweather, clash in a welterweight unification bout appropriately billed as ‘Fight of the Century’.

Boxing’s most lucrative bout has taken almost five years in the making, with Mayweather's WBC and WBA titles and the WBO title owned by Pacquiao at stake.

Also on the line is Mayweather's unbeaten record. 

Their fight will also go a long way to defining each other's careers: whoever wins will be able to claim they were the greatest fighter of their era, rightly or wrongly. As for the loser, there will be an awful lot of soul-searching to do. 

Mayweather says he is going to come out swinging against Manny Pacquiao tonight. The American plans to be the early aggressor in the fight in which he is estimated to earn about $180 million against $120 million for the Filipino.

"I am going to approach it in a very, very aggressive way and go out there and press the attack early," Mayweather said on a television shown last Thursday.

"Of course I would love to win by knockout. I am pretty sure he is going to come at me extremely strong. I am facing one of the best fighters I have ever faced."

However, Pacquiao has warned his American opponent that he has rediscovered his killer instinct in time for their Las Vegas superfight.

Pacquiao was at the peak of his powers in 2008-2009 when he amassed four successive knockouts, including the notable scalps of Oscar De La Hoya, Ricky Hatton and Miguel Cotto.

Of his nine fights since crushing Cotto, the only one that failed to last 12 rounds was when he was flattened by Juan Manuel Marquez in 2012.

The Filipino southpaw enters his 65th fight as underdog for the first time since dismantling De La Hoya and he is revelling amid the widespread expectation that Mayweather will prevail at the MGM Grand.

"I'm so happy because the feeling of the killer instinct and the focus that I had years ago is back," Pacquiao said.

Lawsuits, hostility between rival promoters and broadcasters and Mayweather's blood testing demands prevented the two finest fighters of their generation from clashing since 2010 until the breakthrough in negotiations came in February.

The answer to years of bar room debate will be delivered when the richest bout in history unfolds in the Nevada desert with unbeaten Mayweather knowing the delay in facing Pacquiao has doubled the value of the fight to an estimated $332million.

"Everything takes time, it's all about timing. I'm glad that we had patience and didn't rush. The time is now, this is the right time for this fight," Mayweather said.

"This fight is not good versus evil, it's about one fighter who is at the top fighting another fighter who is at the top. It's about giving excitement.”