On August 2, 1997 Mosley fought for his first world title, the IBF Lightweight championship against then undefeated titleholder Philip Holiday (31-0, 16 KOs). Holiday was making his seventh defence of the title since winning the then vacant title in 1995. It took place at the Mohegan Sun Casino in Uncasville, Connecticut and was the first time Mosley was scheduled to box 12 rounds. The fight went the full 12 round distance as Mosley took Holiday's IBF title via a unanimous decision. The three judges scored the fight 116-113, 117-111, 115-114 all in favor of Mosley.