PHOENIX (AP) - Julio Cesar Chavez already was preparing for retirement. An unexpected loss on his farewell tour persuaded the 43-year-old fighter to stop earlier than planned.

He announced his decision Saturday night after he quit following the fifth round of his bout with journeyman Grover Wiley.

Chavez (107-6-2) lost the scheduled 10-round welterweight fight, complaining of pain in his right hand. The Mexican's handlers said his hand was broken, and promoter Bob Arum said Chavez told him he would not fight again.

Chavez seemed in control in the first couple of rounds. But Wiley kept coming back after Chavez. In the fifth round, Wiley twice used combinations to the head that appeared to hurt Chavez. As Chavez headed to his corner after the round, he looked at his trainers and shook his head, indicating that he was done.

Wiley (29-7-1) of Omaha, Neb., said Chavez quit because he was beating him.

"He can use all the excuses," the 30-year-old Wiley said. "They said it couldn't be done, but we did it. We beat him. We shocked the world."

Chavez's 19-year-old son, Julio Cesar Chavez Jr., who was also on the card, said he would avenge his father's loss and fight Wiley.

Chavez Jr. had little trouble stopping Corey Alarcon of Denver at 1:35 of the second round in a super lightweight bout. Chavez Jr. (22-0) had his nose bloodied in the first 30 seconds of the bout, but that was the only damage inflicted by Alarcon (12-11).