On 30 July 2009, Heinze joined Marseille on a two-year deal for an undisclosed fee, reuniting at the Ligue 1 club with countryman Lucho González. In his first year he scored a career-best four league goals in 27 matches, as "L'OM" won both the national championship and the season's Coupe de la Ligue. On 27 March 2010 he was a starter as his team defeated Bordeaux in the latter competition's final, for Marseille's first major title since 1993; on 5 May, he netted the opener in a 3–1 home win against Rennes, which clinched the league. Manager Didier Deschamps later described the season's events as an "extraordinary human adventure".