Demetrius Andrade won the vacant World Boxing Organization middleweight title with a 12-round unanimous decision over Walter Kautondokwa of Namibia on Saturday.
Kautondokwa was a replacement for Billy Joe Saunders. Saunders tested positive for a stimulant in a drug test administered by the Voluntary Anti-Doping Agency.
The WBO stripped Saunders of his title after the Massachusetts State Athletic Commission declined to give him a license in a hearing on October 9.
Andrade [26-0, 16 knockouts] dropped Kautondokwa four times in the first four rounds, once in the first and third and twice in the fourth.
Two judges scored the fight 120-104, and the other had it 119-105.
Andrade, of Providence, Rhode Island, previously held junior middleweight titles in the WBO and World Boxing Association. He was a member of the 2008 U.S. Olympic team.
Kautondokwa, a 32-year-old WBO African middleweight champion, dropped to 17-1 with 16 knockouts.