For the 2003 season, Martí replaced Luís Moya as the co-driver to double world champion Carlos Sainz. The pair won the 2003 Rally of Turkey and the 2004 Rally Argentina, and helped Citroën to two manufacturers' world titles. After Sainz's retirement from the WRC, Martí began co-driving to Sainz's young protégé Dani Sordo. They won the Junior World Rally Championship in 2005 and made a successful transition to WRC level the following year, recording four podium finishes. After the 2010 Rally Finland Sordo announced that he will have a new co-driver, Diego Vallejo, in the next rally. Martí stated that he had planned to retire after the 2010 season, but now the retirement happened a bit earlier. In December 2013, it was announced he would join Hyundai Motorsport and return to co-drive for Dani Sordo for the 2014 WRC campaign.