For a world-class fighter, Diego Corrales sure has a lot of problems with mouthpieces.

A cheap one cost him a potential victory in his first fight with Joel Casamayor in October 2003, when the end of the mouthpiece managed to become sharp and puncture the area above Corrales' lip.

That created a stream of blood, causing ringside physician Margaret Goodman to rule that Corrales was unable to continue.

In his epic victory in May over Jose Luis Castillo, Corrales' mouthpiece again was an issue. It popped out twice in the decisive 10th round -- intentionally, many in Castillo's camp angrily allege -- and, the critics say, helped buy him enough time to recover from a pair of knockdowns to stop Castillo.

The Las Vegas resident insists the mouthpiece will no longer be an issue. He's bought what he says is a better-quality one for tonight's rematch at the Thomas & Mack Center.

"Believe me when I tell you this fight won't be won or lost because of a mouthpiece," Corrales said.

It's laughable how much attention the mouthpiece has received. Many think it was the deciding factor in Castillo-Corrales I.

Under that line of reasoning, Corrales got extra time after each knockdown to regain his senses when referee Tony Weeks escorted him to the corner and trainer Joe Goossen slowly and deliberately replaced the mouthpiece.

Weeks has somehow managed to come under criticism for his handling of the situation, curious because he handled the fight magnificently and followed the rules exactly as they were written.

They're good theories, but they overlook one central fact: Corrales was clearheaded and ready to fight on each occasion after he got off the mat. In both instances, he still had fight-stopping power in both hands.

Corrales conceded he was "buzzed pretty good" after the first knockdown. But just two or three seconds after hitting the mat, he was clearheaded enough to search for his wife, Michelle, in the crowd and wink at her to let her know he was OK.

This is a guy, remember, who has plenty of experience being knocked down. He's one of the rare world-class fighters who gets knocked down frequently. The two 10th-round knockdowns against Castillo were the ninth and 10th times in Corrales' 42 pro fights that he'd been on the canvas.

But he's a nonstop hunter and always on the attack, which puts Corrales in range of punches that other, more cautious boxers don't get hit with.

"But remember one thing: He always -- always -- gets up," Goossen said.

After the second knockdown, Corrales said, he was fine, and his actions would indicate he's not lying.

He took the count on a knee and popped up at nine, willing to wait as long as he could to catch his breath.

And, just like after the first knockdown, he again looked over at his wife and winked.

The mouthpiece was knocked out the first time by a punch, so Corrales can't be blamed for that.

The second time, he took it out voluntarily and tried to hold it in his glove.

"I was trying to breathe," he said. "It's something a lot of guys do. I pulled it out to get my breath, but it's hard to hold."

He'll pay a dear price if he tries that tonight. If referee Joe Cortez rules the mouthpiece was intentionally removed, a new Nevada Athletic Commission policy allows him to deduct two points, instead of one. Though one would think Corrales has learned his lesson.

Castillo has done dozens of interviews and has been asked hundreds of questions about the mouthpiece this week.

And while Castillo justifiably says he is not happy with the amount of time it took to replace Corrales' mouthpiece, not once has he said he felt Corrales intentionally removed it.

He knew Corrales was still dangerous. Castillo, after all, was the guy taking the bombs a weary Corrales was throwing at the end of the ninth round.

That was a big round for Castillo, one he had won on all three judges' cards, but Corrales hit him with a hook at the end of the round that nearly ended the fight then.

The difference in the first fight, just as it will be tonight, was that Corrales hits slightly harder than Castillo. The fact that Castillo failed to make weight three times Friday and spent a lot of time in a sauna won't do much to help.

In a fight between two men so closely matched, those advantages are what will guide Corrales to victory.

Kevin Iole's boxing column is published Saturday. Reach him at 396-4428 or at kiole@reviewjournal.com.