David Defiagbon was already a well-known figure in his native Nigeria when he won the welterweight title at the 1990 Commonwealth Games. By the time of the 1992 Summer Olympics he had moved up to the light-middleweight division, but was defeated by Raul Marquez of the United States in the opening round of the tournament. Shortly after the Games he fled Nigeria, due to what journalists described as either religious or political oppression, and arrived in Halifax, Nova Scotia in 1993. He gained his citizenship in 1996 and won both the Olympic trials and the Canadian heavyweight title that year, assuring him a place on the nation’s delegation to that year’s Summer Olympics. After a bye in the opening round, he defeated Ahmed Rajab Omari of Kenya and then prevailed in the quarter-finals when his opponent, Christophe Mendy of France, was disqualified for a below-the-belt hit that left Defiagbon unable to continue the fight. Two days later he was sufficiently recovered to defeat Nate Jones of the United States and advance to the final, where he was soundly defeated by Cuba’s Félix Savón, the defending champion who would go on to claim the crown a third time at the 2000 Games.
After earning his silver medal, Defiagbon turned professional and won his first 21 bouts, remaining undefeated until 2004, when he fell to Oleg Maskaev, future world heavyweight champion. A second loss in 2005, against former world cruiserweight champion Juan Carlos Gómez of Cuba, led to his retirement from active competition. At the conclusion of the 2012 Summer Olympics, he remains the last Canadian boxer to have won an Olympic medal. Outside of sports he worked as a security guard.
Canada 
Nigeria