By Rick Reeno

StubHub Center, Carson, California - WBA interim-welterweight champion Keith Thurman (23-0, 21KOs) stopped veteran Julio Diaz (40-10-1, 29KOs) in three rounds, after Diaz suffered a rib injury and was unable to come out for the fourth.

Thurman with the power edge in the first, landing some heavy lumber with both hands. Diaz took the punches well and attempted to return fire. In the second Diaz was rocked and eventually went down after a delayed reaction. The round closed with the two of them trading punches. The third round was all-action, with punches flying from both fighters. Before the start of the fourth, Diaz retired on his stool with a rib injury after the corner notified the referee that he couldn't continue.