Daniel Ponce De Leon claimed Jhonny Gonzalez's WBC featherweight title with a unanimous technical decision Saturday night when their bout was stopped in the eighth round because of a cut over Gonzalez's eye.

Marcos Maidana stopped Jesus Soto Karass 43 seconds into the eighth round of a thrilling, back-and-forth welterweight bout on the undercard of Saul "Canelo" Alvarez's 154-pound title defense against Josesito Lopez.

Leo Santa Cruz also defended his IBF bantamweight title by stopping veteran Eric Morel, who quit on his stool after the fifth round.

Ponce De Leon (44-4) posted an impressive comeback win over Gonzalez despite a big cut of his own on his skull. Gonzalez had won 12 straight fights, claiming the featherweight title in April with a decision over Elio Rojas.

But Ponce De Leon, a Mexican who fights out of the Los Angeles area, is among the sport's most reliably entertaining fighters, from his long braided hair and colorful trunks to his heedless fighting style. Gonzalez fought well in the early rounds, but Ponce De Leon fought through his own cut and gradually turned the bout in his favor.

"I thought I dominated him from the first round," Ponce De Leon said. "He didn't want to fight any more (after the cut). You could tell."

Gonzalez got the nasty cut over his right eye from an accidental clash of heads in the eighth round, and the ringside doctor swiftly called off the fight. Two judges scored it 79-72 for Ponce De Leon, and the third had it 77-74.

"It was a good fight, but it was the style of the southpaw and the right-hander that caused the head butt," Gonzalez said. "I want the rematch, but in Mexico, not on my opponent's turf."

Golden Boy offered a $100,000 bonus for the best knockout victory in a show dubbed "Knockout Kings," and Maidana did his best to claim it.

Maidana (32-3, 29 KOs) and Soto Karass put on two spectacular performances in a bout that's likely to rank among the year's best. Maidana again proved to be one of the sport's most entertaining stars, even attempting to outperform his fellow Argentine, Sergio Martinez, who had his own middleweight fight down the street at the Thomas and Mack Center.

"I knew he was going to be tough, but I knew I could win," Maidana said.

Maidana, a brawler who lost to Devon Alexander in his welterweight debut in February, punished Soto Karass (26-8-3) with big left hooks in the first three rounds. The fighters then got into a post-bell scuffle after the third round, with both men's trainers coming into the ring to break up the confrontation — and nearly getting into their own rumble.

Referee Kenny Bayless took points from both men for low blows and hitting out of breaks in the fourth round, and Maidana appeared to lose energy shortly afterward, allowing Soto Karass to take control.

"I didn't care when they took away the points," Maidana said. "I knew I would come back."

After another confrontation after the fifth round, Maidana got his mojo back. Bayless took another point from Maidana in the seventh round for low blows, but Maidana then put Soto Karass on the canvas late in the round with a huge right hand, sending Soto Karass partly through the ropes.

Maidana finished off Soto Karass early in the eighth, battering him with right hands and combinations until Bayless had to step in.

"It was a war like I predicted it would be, but I think the ref stopped it too soon," Soto Karass said.

Santa Cruz (21-0-1, 12 KOs), who won his title in Carson, Calif., in June, cemented his status as an up-and-coming star with five rounds of vicious punishment for Morel (46-4), who had never been stopped in his 16-year career.

Santa Cruz, a Mexican who fights out of Rosemead, Calif., battered Morel with body shots and jabs, picking apart a sturdy longtime contender. Morel, a Puerto Rican who lives in Madison, Wis., said he's considering retirement.