Born in Sapele, Nigeria, Defiagbon won gold in the welterweight (– 67 kg) division at the 1990 Commonwealth Games. As a light-middleweight, he won a bronze medal in the 1991 All-Africa Games in Cairo. In 1992 in Barcelona at the Summer Olympics he represented Nigeria and was eliminated in the first round of the light middleweight division (7 to 8 against Raúl Márquez).
1990 Commonwealth Games
- Defeated James Pender (Scotland) RSCH-3
- Defeated Alfred Ankamah (Ghana) 5-0
- Defeated Anthony Mwamba (Zambia) 4-1
- Defeated Greg Johnson (Canada) 5-0
1992 Summer Olympics
- Lost to Raúl Márquez (United States) 7-8
1996 Summer Olympics
- 1st round bye
- Defeated Omar Ahmed (Kenya) 15-4
- Defeated Christophe Mendy (France) DQ 3 (1:01)
- Defeated Nate Jones (United States) 10-16
- Lost to Félix Savón (Cuba) 2-20
Defiagbon began his professional career that same year and won his first 21 fights against limited competition, and was a significantly undersized heavyweight with little power although he was 6 ft 5 in (196 cm) tall. In his first step up, he took on comebacking Oleg Maskaev, who defeated Defiagbon via split decision. In his final bout, Defiagbon fought Cuba's former world cruiserweight champion Juan Carlos Gomez, who scored a TKO stoppage win at heavyweight over Defiagbon in the third round, ending Defiagbon's career.
Professional boxing record
Defiagbon died of heart complications in Las Vegas, Nevada on 24 November 2018. He was 48.