In 2004, the French teenager finished as the world's No. 1 junior, winning the first three of four junior Grand Slam events (Australian Open, French Open and Wimbledon). He improved his ATP Entry Ranking by over 700 positions. In October, he made his ATP debut as a wildcard entrant at the Moselle Open in Metz and, after winning his first ATP match against Xavier Malisse, reached the quarterfinals in which he lost to countryman Richard Gasquet. He qualified for the 2004 Paris Masters and reached the second round, beating former Top 10 player Thomas Enqvist before falling to world No. 3 Lleyton Hewitt. He won junior titles at the Australian Open, French Open (defeating Alex Kuznetsov) and Wimbledon. He did not drop a set in Australia and lost one set each at the French Open and Wimbledon. He reached the third round at the US Open (losing to Viktor Troicki). He also won the LTA International Junior Championship in Roehampton (defeating Andy Murray). He was the runner-up at the Australian Hardcourt Junior Championships (losing to Mischa Zverev) and was 31–2 in junior events. In April, he reached his first career Futures final at the Italy Futures No. 4. A week later, he won his first Futures title at the Great Britain Futures No. 1 (defeating Alex Bogdanović). He reached the quarterfinals of the Grenoble Challenger. He went 14–6 in Futures and 3–5 in Challengers in 2004.