Sergio Martinez gave Julio Cesar Chavez Jr. the beating he promised for 11 rounds, then barely survived being knocked out in the final round Saturday night to regain the middleweight title.

Martinez was quicker, busier and far more accurate as he won round after round to give Chavez his first loss and disappoint the majority of a crowd of a sellout crowd at the UNLV campus arena.

But a bloodied and battered Chavez dropped him with a pair of left hooks in the 12th round, then put him down again. Chavez was landing big punches to the head as the bell sounded to save Martinez.

Martinez won 118-110 on two ringside scorecards and 117-110 on the third. The Associated Press had him winning 118-110.

"I was 20 seconds away from knocking him out. I started way too late," Chavez said. "I didn't really get started until the eighth round."

Martinez said before the fight he didn't consider Chavez a true champion, and then he made sure Chavez didn't look like one until he ran into trouble in the final round. And what trouble it was, with Martinez coming off the canvas twice and was in deep trouble when the round finally ended before a thunderous crowd of 19,186.

"He fought a great fight and he was a lot tougher than I expected," Martinez said. "He showed great heart."

The wild ending nearly ruined what was a great night for the Argentine fighter who used his speed and boxing skills to dominate until the final round. Chavez was bleeding from the nose, his face was marked up and he looked finished until suddenly landing a huge left hook to drop Martinez for the first time.

Martinez got up only to take several more head punches and go down once again. Chavez kept after him when he got back up, trying desperately to land the finisher before the bell sounded and the decision was lost.

"If Julio wants a rematch, we'll do a rematch," Martinez said.

The comeback was reminiscent to one by his father in 1990 against Meldrick Taylor, when he came back from seemingly certain defeat in the last round to stop Taylor with 2 seconds left in the fight.

"You hit very hard," a victorious Martinez told Chavez.

Martinez fought his fight in the early rounds, using his jab and speed to keep Chavez off balance. Fighting out of a southpaw stance, he stayed on his toes, moving around on the outside and seldom allowing Chavez in where he could cause damage.

The action picked up in the fourth round as Chavez found Martinez with a good right, only to take a series of punches from his quicker opponent. At one point in the round, just after Chavez complained of a low blow, Martinez landed a right-left combo, then taunted Chavez.

Until the wild 12th round it was much of the same, with Martinez winning every round on two of the judges' scorecards and all but one on the third. Chavez picked up the pace late, but it wasn't until he caught Martinez with the left hook that the fight turned wild.

"I knew Martinez was good," said Freddie Roach, the trainer for Chavez. "I didn't know how good. This was a good lesson for Julio, he needed to let his hands go sooner."

The fight was part of a big fight night in this gambling city. Just a few blocks away from where Martinez and Chavez did battle, Mexican sensation Saul "Canelo" Alvarez stopped Josesito Lopez in the fifth round to keep his WBC 154-pound title.

Chavez earned his biggest payday, $3 million guaranteed, while Martinez got $1.4 million plus a percentage of the pay-per-view sales.