consecutive title at the Countrywide Classic in Los Angeles, beating Andy Roddick in straight sets in the final. After the match, Roddick praised his opponent. "[Del Potro] hits this way and this way kind of equally and he can hit it from inside out and running to it, which is a good thing for him, bad for the rest of us". A fourth consecutive title followed a week later in the Legg Mason Tennis Classic in Washington, D.C., where he recorded a victory over Viktor Troicki, becoming the first player in ATP history to win his first four career titles in as many tournaments. "I don't really understand what I did. It is difficult to believe that I have won four consecutive titles", del Potro said, crediting coach Franco Davín for his impressive run. "He changed my game. He changed my mind. He changed everything. When I play and I see him in the stands, it gives me confidence. I can play relaxed." At the 2008 US Open, del Potro progressed to the third round, where he won his first match to five sets in the circuit against Gilles Simon to reach the round of 16. He went on to defeat Japanese teenager Kei Nishikori in straight sets. In the quarterfinals, he was stopped by eventual finalist Murray, losing after almost four hours. The defeat came after 23 consecutive victories: the second-longest winning streak in 2008 and the longest winning streak by a player outside the top 10 in the last 20 years. Del Potro was selected to play his first home-based Davis Cup tie, between Argentina and Russia. He won his first singles match against Davydenko in three sets. He also won the fifth and deciding match against Igor Andreev in straight sets, booking Argentina a place in the final. At the AIG Japan Open Tennis Championships, he made the final by defeating 11th seed Jarkko Nieminen, top seed and defending champion Ferrer, and fourth seed Richard Gasquet. He was defeated by Tomáš Berdych in the final. At the Madrid Masters, he lost in the quarterfinals in straight sets to Roger Federer. He reached the semifinals of his next tournament, the Davidoff Swiss Indoors, before losing to countryman Nalbandian. He was beaten by Nalbandian again in his next tournament, this time it was in the second round of the Paris Masters. Del Potro blamed fatigue for his defeat, "It's