LAS VEGAS -- Paulie Ayala beat Bones Adams in a unanimous decision Saturday night to retain his IBO super bantamweight title in a rematch of a close bout last August.

Ayala dominated throughout, winning on scores of 118-110, 118-110, and 117-111.

"It was easier this time," said Ayala (34-1). "I studied the videotapes and found a double-jab would work very well. I tried to take him out but I couldn't."

Ayala won the first fight on a split decision.

A standard 10-9 round scoring would have resulted in the fight being ruled a draw. Ayala was the aggressor throughout the fight, even though he never really hurt Adams (41-5-3).

Compubox scoring had Ayala out-punching Adams (41-5-3) 353-216 in Saturday's bout. Adams won the eighth and ninth on two cards. He connected to Ayala's head with a combination at the end of the eighth, but it wasn't enough to hurt the champion.

"I should have fought like the last time, toe-to-toe," Adams said.

After the fight, Ayala said he plans to move to featherweight to fight the winner of the Marco Antonio Berrera and Erik Morales WBC title fight scheduled for June 22.

"I won't have any problem going up in weight," Ayala said.

Also on the card, Rafael Marquez knocked out Mark Johnson in 2:41 of the eighth round to claim the vacant USBA bantamweight title.

Marquez (27-3, 25 knockouts) knocked Johnston down twice in the eighth and once in the seventh. Marquez outlanded Johnson 27-4 in the eighth.

The fight was a rematch of an Oct. 6 bout in Corpus Christi, Texas, in which Johnson (40-3) was announced as the winner, but two hours later the decision was changed because the scorecards weren't added up properly.