[1][6][7] Mahut, who had settled in Fontainebleau during his childhood, joined the youth team of that town's local club, Entente BFN.
Thanks to his good footballing qualities and his fine performances in the Division 2 matches, he rapidly attracted the attention of player scouts.
[3][6][8] In July 1976, Mahut joined Troyes (whose head coach was then René Cédolin), initially signing a contract as a semi-professional.
After having signed a contract as a full-fledged professional for the first time in his football career, he played 26 leagues matches in his second and final season at Troyes, at the end of which they were relegated to Division 2.
[6] Not wanting to play in Division 2 in the 1978–79 season, Mahut decided to leave Troyes and join Metz, which had offered him a contract.
In his first season at the club, Mahut integrated well into the team, formed a centre-back partnership with Wim Suurbier and made 32 league appearances.
[8] During the summer of 1980, the club saw the departures of several key players, including Patrick Battiston and Philippe Redon.
He soon left Metz for Saint-Étienne for a transfer fee of two million francs, an enormous sum at that time for a defender.
The club experienced a difficult 1982–83 French Division 1 season, during which their head coach for the past 11 years, Robert Herbin, was sacked (in February 1983) and replaced by Guy Briet.
In that competition, Saint-Étienne was eliminated 4-0 on aggregate by Bohemians CKD Praha in the second round and Mahut played all the 4 matches the club was involved in but he did not score any goals.
[8] The summer of 1983 really marked the end of the club's golden era, with the departure of good players like Patrick Battiston, Bernard Genghini and Gérard Janvion, etc.
[6] RC Paris had bad match results during the first half of the 1984–85 French Division 1 season, which cost head coach Alain de Martigny his job in January 1985.
[8] In order to perform well in the 1986–87 French Division 1 season, Racing Club de Paris broke the bank by signing high-quality, foreign and French internationals (Bernard Bureau, Luis Fernandez, Enzo Francescoli, Bruno Germain, Pierre Littbarski, Pascal Olmeta, Rubén Paz and Thierry Tusseau) as well as good, non-international players from France (Loïc Pérard and Jean-Luc Le Magueresse) in the middle of 1986.
Despite the heavy investments in these star players, the club did not meet its own high expectations - it only finished in 13th position in the 1986–87 Division 1 table.
In the summer of 1987, the club hired a new head coach, Artur Jorge, who had just guided Porto to victory in the 1987 European Cup Final.
Four new players - Gérard Buscher, Merry Krimau, Thierry Fernier and Sonny Silooy - were signed for the 1987-1988 season.
It was thus beaten to the Division 1 promotion play-offs by Rennes, which finished Group A in third position level on points with Stade Quimpérois but with a superior goal difference.
[11] The 1989–90 season would prove to be a difficult one for the players of Stade Quimpérois because the club was experiencing major financial problems.
During the first half of the 1989–90 Division 2 season, Jean-Pierre Hureau, who was then the president of Le Havre, traveled to Quimper to talk Mahut into joining his club.
[8][11] In October 1989, Mahut signed a two-year contract to join Le Havre (which was then in Division 2), where he became the club captain.
Several new players - Graham Rix, Václav Daněk, Thierry Goudet, Pierre Aubame, Patrice Garande, Jean-Christophe Thouvenel and Teddy Bertin - were signed for the 1991-1992 season.
[14] Between 1981 and 1983, Mahut earned a total of 9 international caps for the France national football team, scoring no goals.
Mahut made his debut for France on 9 September 1981, in a 1982 World Cup qualifying match against Belgium at the Heysel Stadium in Brussels.
[6][15] His final international appearance for his country was on 23 March 1983 in a friendly match against the Soviet Union at the Parc des Princes stadium.
In that project, the demolition of the old spectator stands were completed in December 2013 and the renovation works were scheduled to finish three years later.
[1][6][7][12] "He (Mahut) will be remembered as a great professional on and off the pitch," said French Football Federation president Noël Le Graët.
The funeral was attended by 800 persons that comprised his family, friends, members of the Fontainebleau town council (including Frédéric Valletoux, the town's mayor) and dozens of his former football teammates such as Patrick Battiston, Maxime Bossis, Luis Fernandez, Yannick Stopyra and Luc Sonor.