Overweight or not, Jose Luis Castillo was still dangerous. With one vicious left hook he stopped Diego Corrales in the fourth round Saturday night to win the rematch of a fight for the ages.

The second fight didn't last as long, but it was nearly as entertaining as Castillo wobbled Corrales in the third round with a right hand and put him to the canvas in the fourth round with a punch that ended the fight.

Castillo landed the left hook flush on the side of Corrales's face and immediately raised his hands in victory as Corrales went to the canvas. Corrales tried to get up and finally did at the count of nine but was wobbly and referee Joe Cortez waved the fight to a close at 47 seconds of the fourth round.

"I knew he wasn't getting up," Castillo said. "I told everyone I would knock him out before the seventh round."

The fight was a rematch of one of the most thrilling fights in years, a bruising battle that ended only after Corrales, of Sacramento, came off the canvas twice in the dramatic 10th round in May to stop Castillo with a flurry of punches.

Both fighters vowed the second fight would be even better, and they went after each other right from the opening bell. Blood was already flowing in the second round when Corrales was cut above the right eye, and Castillo wobbled him in the third with a right hand.

Castillo (53-7-1, 47 knockouts) nearly missed his chance for revenge on Friday by weighing in at 1381/2 pounds, over the lightweight limit of 135 pounds. But the fight went on anyway, title or not, and some 15,000 fans attended.

Corrales (40-3) tried to fight the same way as he did in the first fight, toe-to-toe with the Mexican challenger. It was a mistake, as he was on the receiving end of harder punches, including the one that finished it.

"I have no excuses," Corrales said. "He hit me with a good shot."

The fight was originally going to be for the WBC and WBO titles held by Corrales until Castillo missed weight on Friday. By the time the two fighters stepped into the ring, though, they were full-fledged welterweights.

Because he missed the weight, Castillo had to weigh in again Saturday afternoon and make 147 pounds -- or pay Corrales $75,000 for each pound over. He weighed in on the mark, while Corrales unofficially was weighed at 149 pounds two hours before the fight by Nevada boxing officials.

Though promoters attempted to still bill the fight as a title fight, the executive director of the Nevada commission, Marc Ratner, said he did not consider it one.

Corrales received $2 million, while Castillo got $1.2 million before paying a $120,000 fine -- split between Corrales and the state of Nevada -- for not making weight.

Referee Joe Cortez, left, counts out Diego Corrales as Jose Luis Castillo stands in his corner in the fourth round of their 12-round bout in Las Vegas.