Alvarez was leading in all score cards up to the seventh round when Mosley came up with his own power assault in round eight.
In round nine, Alvarez resumed his attack on the aging Mosley which he followed through until the end of the12-round fight.
Judges scored the fight
at 119-109-118-110-119-109 to the winner, Saul "Canelo" Alvarez, by unanimous decision.
The aging Mosley is coming off a loss to pound-for-pound king Manny Pacquiao in May of last year via a unanimous decision.
Mosley, 39, has yet to announce his retirement after 55 professional fights, winning 46 and losing seven with one draw.
The Alvarez vs. Mosley fight was the main undercard
in the fight between unbeaten Floyd Mayweather, Jr. and WBA Junior middleweight champion Miguel Cotto of Puerto Rico.