[1] On 13 November 2004, L'Heureux challenged Steve McKay (record 5–1) for the vacant Canadian heavyweight championship in Montreal.
However, in his first fight after winning the prestigious title in 2005, L'Heureux was viciously pummelled by American clubfighter Steve Pannell (33-8) to lose his undefeated ring record by a technical knock out at 2:31 of the first round.
[citation needed] The 6-foot 5-inch tall right-hander suffered his second loss when he was knocked out in the seventh round by David Cadieux on 12 May 2006.
On 26 May 2007, he suffered his fourth loss to the undefeated Alexander Povetkin by a knockout in the second round.
His first fight with Tessier earned L'Heureux the Quebec Boxing Council (CQB) Heavyweight Title.