Petiot was drafted 116th overall by the Los Angeles Kings in the 2001 NHL Entry Draft. Petiot began his hockey career playing for the Colorado College of the NCAA. After finishing his junior season, Petiot assumed a larger role on the team, as graduation removed many of Colorado's key players. In 2004-05, Petiot finished his college eligibility, allowing him to join an NHL franchise. However, two seperate injuries plagued his season, but Petiot still maintained his physical style of defense that was responsible for any of his playing success. During the 2004-05 offseason, Petiot signed a two year contract with the Kings.
Petiot began the 2005-06 season with the Manchester Monarchs, the AHL affiliate of the Kings. Petiot was called up to Los Angeles on four seperate occasions during the season, but played in only 2 NHL games, recording no points. Petiot returned to Manchester, has not played in an NHL game since.
Petiot missed nearly the entire 2006-07 season with the Monarchs after severely tearing tendons in his knee. Petiot suffered during his return to action, as he was unable to play at the level he had before the injury, where he was arguably the Monarch's best defenceman.
Petiot was signed by the Toronto Marlies before the start of the 2008-09 season. He has since become a regular member of the Marlies' defensive core.