CHICAGO, AUG. 11 -- Edwin Rosario scored a technical knockout over Puerto Rican rival Juan Nazario in the eighth round tonight to retain his World Boxing Association lightweight title.

Rosario cornered Nazario, then pummeled him with a combination of punches to end the bout at the University of Illinois-Chicago Pavilion before about 2,300.

Nazario was cut over the right eye in the fourth round. Rosario took control of the fight from that point after pacing himself in the earlier rounds.

The fight was called at 2:43 of the eighth round after Rosario nailed Nazario with a right jab, knocking him to the canvas. Nazario was bleeding heavily from several cuts.

All three judges had Rosario ahead on their scoring cards, 69-65, when the fight ended.

Rosario's record improved to 26-2, with 22 knockouts. Nazario fell to 18-1-1. Both boxers started training in the same San Juan gym. Before the fight, the former friends said the bout was "a blood feud" to see who was the better boxer.

Rosario, 24, weighed in at 134 3/4 pounds; Nazario, 23, came in at 134 1/2.

As he entered the arena and moved toward the ring, Rosario was followed by WBA heavyweight champion Mike Tyson, who stayed in his corner throughout the fight.

Nazario came out in the early rounds and directed a number of punches at Rosario's stomach and kidney area.

He was warned in the opening round by referee Carlos Berrocal from Panama. But Nazario continued punching that area of Rosario's body in the second and third rounds. Nazario also was warned about punching after the break.

The winner earned $150,000 from the fight. Nazario made about $28,000.