In 2003, Gaultier was a member of the French team which finished runners-up to Australia at the World Team Squash Championships. In the semi-finals against England, Gaultier won the deciding match against Lee Beachill which took France through to the final.
At the 2006 World Open, Gaultier defeated World No. 1 and defending-champion Amr Shabana in the semi-finals, before losing in five games in the final to David Palmer 11–9, 11–9, 9–11, 10–11 (4–6), 2–11. In 2007, Gaultier again reached the World Open final, losing 7–11, 4–11, 6–11 to Shabana.
At the 2007 British Open, Gaultier defeated his fellow Frenchman Thierry Lincou in the final 11–4, 10–12, 11–6, 11–3. He became the first French winner of the British Open.
At the 2009 Tournament of Champions, Gaultier defeated the world No.1 Karim Darwish in the semifinal, and beat Nick Matthew in the final with a score 11–9, (2–11), 11–8, 11–4. He is the only Frenchman to have won the title.
Gaultier moved to the top of the world ranking in November 2009, a feat achieved after losing in the final of the Hong Kong Open a month earlier.[1] In 2009 he became the second French player to become world no 1.[2]
In February 2014 he once again reached the top of the World Ranking, but again only for a month, as was the case in November 2009. One month later, in March, he won the Metro Squash Windy City Open, another PSA World Series tournament in the University Club of Chicago beating the apparently injured Ramy Ashour in the final 11–7, 11–3, 11–4. In April he reached World Number 1 ranking for the third time.
In May he won the British Open for the second time beating Nick Matthew in a very quick final 11–3, 11–6, 11–2.
In October 2021 Gaultier announced his retirement from the PSA World Tour.[3]