Saul Alvarez stops Alfonso Gomez

LOS ANGELES -- Saul "Canelo" Alvarez kept his 154-pound title belt Saturday night, stopping Alfonso Gomez at 2:36 of the sixth round.

Alvarez (38-0-1, 28 KOs) started and finished strong in his bout on the undercard of Floyd Mayweather's victory over Victor Ortiz. The wildly popular Mexican fighter met Gomez at Staples Center in a two-city pay-per-view card.

Alvarez knocked down Gomez (23-5-2), from nearby Anaheim, with a compact left hook late in the first round. Gomez, who fought on the reality television series "The Contender," rallied in the next few rounds and hung in with the hard-punching Alvarez.

But Alvarez dominated the fifth round, and he finished Gomez with a nasty uppercut and several big shots. Gomez thought referee Wayne Hedgpeth stopped the fight too soon, with Alvarez raining blows on Gomez's defense.