He won his first title of the year at the Monte Carlo Masters, which he defended by defeating Guillermo Coria, 6–2, 6–2. In his next four tournaments, he reached the semi–finals in Torneo Godó, losing to Marat Safin, 4–6, 3–6, and the semifinals at the 2003 Rome Masters retiring against Roger Federer, 4–6, 2–4 with a shoulder injury. He also won the Valencia Open, defeating Christophe Rochus, 6–2, 6–4, without losing a set. He then won his first and only Grand Slam at the 2003 French Open, defeating surprise finalist Martin Verkerk, 6–1, 6–3, 6–2, in the final. He reached the 4th round of Wimbledon losing to Sébastien Grosjean 2–6, 6–4, 6–7(2–7), 6–7(3–7). He reached back–to–back quarterfinals at the Generali Open losing to Mariano Zabaleta 1–6, 4–6 and at the Idea Prokom Open losing to Luis Horna 1–6, 6–7(1–7).