Drumond turned professional in February 2005 at the Limon, Costa Rica. On his debut as a professional, Drumond faced Miguel Osorio, who he dispatched in the first round. The referee decided to stop the fight after the sixth round as blood was coming out of that cut Chagaev sustained.
He lost his next fight against Derric Rossy on 31 July 2009 by unanimous decision.
Upon winning all his first 26 matches (one win was over former IBF-cruiserweight-champion Kelvin Davis (boxer)) Drumond challenged Ruslan Chagaev for the WBA heavyweight title on (7 February 2009). Chagaev won on technical decision after Drumond accidentally head-butted him twice in the third and fourth rounds, leaving Chagaev with a cut on his left eye. The judges all had Chagaev in front on the scorecards, so he was declared the winner according to WBA-rules.
