[1] The bout was held at the MGM Grand Garden Arena in Las Vegas, Nevada, United States.

[5] Mayweather has had one previous fight in the 154-pound division, which was when he outpointed Oscar De La Hoya to win a belt in May 2007.

Mayweather reclaimed one of his old welterweight titles by knocking out Victor Ortiz controversially in the fourth round at the MGM Grand on Sept. 17, 2011.

[6] Making the third defense of his title, Cotto was in a fight without Top Rank as his promoter for the first time in his career.

His contract with Bob Arum's company expired following his Dec. 3 revenge, 10th-round knockout victory against Antonio Margarito and he will be working with Golden Boy Promotions, Top Rank's archrival, on the fight with Mayweather.

Both fighters agreed to random blood and urine testing for the fight, which Mayweather had demanded of his most recent opponents at the time.

Shane Mosley is a tremendous fighter with a lot of experience and big victories in his storied career.

"[9] Mosley would perform better than he had in his previous bouts but Alvarez was able to take advantage, landing numerous clean right hands and left hooks.

The fight lasted the full 12 rounds with Álvarez winning a one-sided unanimous decision with scores of 119–109, 119–109 and 118–110.

Then from rounds 4-9 the action was closely contested, with both fighters using their partially contrasting styles in attempts to one-up the other.

When they hugged at the end, Mayweather told Cotto, "You are a hell of a champion — the toughest guy I fought.