Two years later, Maguire reached the final of his first world ranking event, the 2004 European Open. Ranked 41st in the world, he defeated Peter Ebdon, Joe Perry (both 5–4), John Higgins 5–3 and Stephen Lee 6–4 to meet Jimmy White in the final. Maguire defeated White in the final to win the championship 9–3, a result the BBC described as a "surprise". Throughout the tournament, Maguire commented on that he couldn't believe how badly his opponents had played against him. Later that season at the 2004 World Snooker Championship he qualified for the 32-man competition for the first time. He lost 6–10 in the opening round to Ronnie O'Sullivan, who admitted to being impressed by Maguire's performance and tipped him to be a future world champion.