PHOENIX - Former super-featherweight champion Joel Casamayor scored a ninth-round TKO over Lamont Pearson in a lightweight bout Friday night.

The 34-year-old Casamayor then issued a challenge on television to acknowledged lightweight champion Diego Corrales, with whom he has split two fights. Corrales, who was in the ESPN2 studios, had a spirited exchange with Casamayor and promoter Luis De Cubas.

"I proved tonight I was the best 135-pounder in the world," Casamayor, who improved to 33-3-1 with 21 KOs, said through an interpreter.

Pearson didn't think so. Although he was badly cut around his right eye, Pearson disputed ringside doctor Robin MacDougall's decision to stop the fight at 44 seconds of the ninth round.

MacDougall said that when he asked Pearson if he wanted to continue, Pearson told him he couldn't see.

"If you can't see, you can't fight," MacDougall said.

There apparently was some miscommunication.

"I thought it was premature," said Pearson, 23-4-1 with 12 KOs. "The doc asked me, 'Could you see.' I said, 'Yeah, I can see."'

Pearson said he wasn't sure when he got cut, but he conceded it was from a punch. In the second round, Casamayor began bleeding from a cut on the top of his head after apparently bumping heads with Pearson.

If the doctor hadn't stopped the fight, it might have been only a matter of time before Casamayor did. Pearson injured his right hand in the sixth round and was reduced to a left jab in the last few rounds.

Casamayor was leading by six points on two cards and four on a third.

Casamayor made $40,000 and Pearson was paid $12,000.