losing to Jo-Wilfried Tsonga. He lost in the first round of Wimbledon, still failing to capture his first win there, losing to Nicolás Almagro in a match that lasted almost four hours. He represented Argentina once again in the quarterfinals of the 2009 Davis Cup against the Czech Republic, losing both his matches. He then competed in the 2009 Swedish Open, defeating eighth seed Máximo González and dominating in his next three matches against Victor Crivoi, top seed Fernando Verdasco, and third seed and defending champion Tommy Robredo, before losing to Robin Söderling in the final. In the 2009 International German Open, he defeated Mikhail Youzhny and José Acasuso. He then lost to David Ferrer in the third round. Monaco competed directly in the 2009 US Open without competing in any events in 2009 US Open Series. He lost to eventual champion Juan Martín del Potro in the first round. At the 2009 BCR Open Romania, Monaco reached his third final of the year, but once again ended as runner-up to Albert Montañés, after defeating qualifiers Júlio Silva and Pere Riba, eighth seed Pablo Cuevas, and German Simon Greul. Because of this final appearance he ended the year with 29 wins on clay, the most wins on clay by any player. In the 2009 Rakuten Japan Open Tennis Championships, he retired against Ernests Gulbis in the second round after defeating Guillermo García López. He then lost to Victor Troicki in the first round of the 2009 Shanghai ATP Masters 1000. He lost to Joachim Johansson, after defeating Jan Hernych in the first round of the 2009 If Stockholm Open. He competed in the 2009 Grand Prix de Tennis de Lyon as the fourth seed, but was upset by Michaël Llodra in the second round after defeating Frenchman Josselin Ouanna in the first round. He lost in the second round of the 2009 Valencia Open 500 to Nikolay Davydenko. He then lost to Novak Djokovic, despite leading 5–3 in the second set, after defeating Jérémy Chardy in the 2009 BNP Paribas Masters. This was his last tournament of the year, reaching three finals; the most since winning three titles in 2007. He ended the year at no. 30. 2010 Monaco started 2010 with the Heineken Open, where he defeated Horacio Zeballos in the first round, but lost to eventual champion John Isner in three sets. He lost to sixth seed Nikolay