Madrid Masters. After defeating Murray for the first time in the quarterfinals, he lost to Federer in the semifinals. At the French Open, where he was fifth seed, del Potro defeated Michaël Llodra, Troicki, Andreev, and ninth seed Tsonga en route to the quarterfinals. He then defeated three-time former quarterfinalist Tommy Robredo to get to his first semifinal of a Grand Slam. He was defeated in a close semifinal, where he was leading by a set twice, by eventual champion Federer who, after their match, said: "[Del Potro] is young and strong, I have a lot of respect for him." Prior to this encounter, del Potro had never taken a set from Federer in their five previous career meetings. At the 2009 Wimbledon Championships, his poor grass-court form from the past continued, as he went down to unseeded Lleyton Hewitt in the second round. In the Davis Cup quarter-final against the Czech Republic, del Potro won his matches against Ivo Minář and Berdych in straight sets, but Argentina still lost the tie 2–3, eliminating them from the competition. A few weeks later, he defeated Hewitt and Fernando González en route to the Washington final. He successfully defended his title against top-seeded Wimbledon finalist Andy Roddick to win his second tournament of the year and become the first player since Andre Agassi to win back-to-back Washington titles. Del Potro played the following week at the Masters 1000 in Montreal, where he was seeded sixth, defeating world No. 2 Nadal in the quarterfinals, his second win in a row over Nadal. He then defeated Roddick in the semifinals, saving a match point, to advance to his first Masters 1000 final, and to improve his head-to-head record against Roddick to 3–0. In the final, he lost against Murray in three sets. He later withdrew from the next Masters 1000 event in Cincinnati due to fatigue. Seeded sixth at the 2009 US Open, del Potro began by defeating Juan Mónaco and Jürgen Melzer in straight sets, before dropping a set but defeating Köllerer to reach the fourth round. He defeated a resurgent Juan Carlos Ferrero to advance to the quarterfinals for the second consecutive year. Del Potro then advanced to the semifinals by defeating Marin Čilić. Del Potro was down a set and a break, before winning 17 of the final 20 games to win the match. His advance to the semifinals ensured his