WBA featherweight champion Leo Santa Cruz (32-0-1, 18 KOs) stopped former IBF super bantamweight champion Kiko Martinez (35-7, 26 KOs) in the fifth round on Saturday night at the Honda Center in Anaheim, California.
Mexican-born Santa Cruz dropped Martinez twice in first round, each time from right hands, but the Spaniard survived and came back with some punches of his own.
The two traded hard shots at close range throughout until the end came in the fifth when Santa Cruz backed Martinez to the ropes and landed a series of punishing punches that prompted referee Raul Caiz Sr to stop the fight at 2:09 of the round.
Santa Cruz was making the first defence of the title he won when he outpointed countryman Abner Mares in August.
Also on the card, Hugo Ruiz (36-3, 32 KOs) dethroned fellow Mexican Julio Ceja (30-2, 27 KOs) in just 51 seconds to win the WBC super bantamweight title in a rematch.
Ruiz dropped Ceja with a right hand in the first round and the referee waved off the bout moments later after the follow up punches. Ceja injured his right ankle when he was knocked down and never recovered.
Ceja got up off the canvas to score a fifth round stoppage in the first fight to win the vacant title last August.