In 2004 Yamaha signed him. After three Supersport World Championship races at the end of the year, he was a Superbike World Championship factory rider for . He finished the season 8th overall, behind teammate Noriyuki Haga who was third. Things improved in as he was 5th overall, and scored his maiden Superbike World Championship win at the Misano Circuit in Italy in June 2006. At the end of the season, he lost his seat to fellow Australian and Superbike World Champion Troy Corser.