In 2003–04, Hunter won the Masters for the third time in four years. Hunter was behind Ronnie O'Sullivan throughout the entire match trailing 1–6, 2–7, 6–8 and 7–9 before winning the final three frames to seal the sixth title of his professional career. He made five century breaks in the match. The same year, Hunter reached the final of the Players Championship, but lost 7–9 against Jimmy White. At the 2004 Premier League Snooker event, he made his career highest break, a 146 in a 3–5 loss to Marco Fu. He reached the second round of the 2004 World Snooker Championship, where he lost 12–13 against Matthew Stevens, despite leading 10–6 and 12–10 at various stages of the match.