Heavyweight Marvis Frazier scored a unanimous 10-round decision today over previously unbeaten James Broad of Wildwood, N.J.

Frazier, son of former heavyweight champion Joe Frazier, avenged a 24-second knockout loss he suffered to Broad in the 1980 U.S. Olympic trials. Frazier overcame a 30-pound weight difference.

Frazier, of Philadelphia, is 9-0 with six knockouts. Broad, 228 1/4, fell to 12-1.

The scoring of judges Frank Brunette, Phil Newman and John Stewart were 5-4-1, 5-4-1 and 6-3-1, respectively, for Frazier.

Frazier hurt Broad in the second round with an overhand right and pounded Broad along the ropes before Broad responded with a right uppercut just before the bell rang.

In the sixth and seventh rounds, both fighters stood toe to toe in the middle of the ring and in the seventh, Broad staggered Frazier with a right hand. But Frazier continued his attack to the body and head for the final three rounds.

The fight was Frazier's third this year after a 17-month layoff because of a pinched nerve in his neck and viral hepatitis.

In an earlier heavyweight bout, Rodney Frazier, nephew of Joe, knocked down Trib Perry of Greensboro, N.C., twice and won by a TKO at the end of the first round.