Middleweight Robbie Sims of Brockton, Mass., a...

Middleweight Robbie Sims of Brockton, Mass., a half-brother to Marvin Hagler, knocked down Lee Sanders of Lake Charles, La., in the first round and went on to win by a TKO in the fifth round of a scheduled 10-round fight Friday night in Las Vegas.

Sims, 160 pounds, is 28-4-2, with 20 knockouts, and is ranked No. 3 by the International Boxing Federation. The unranked Sanders, 159, is 13-3.