Levine, and Grega Žemlja before advancing past the fourth round for the first time in his career, thanks to a win over Andreas Seppi. He then played David Ferrer and, despite slipping badly during the fifth point of the match and aggravating a pre-existing leg injury, requiring over five minutes of treatment and by his own admission being close to forfeiting the match, he recovered to defeat Ferrer in straight sets to advance to his first Grand Slam semifinal since the 2009 US Open without dropping a set. On 5 July, Djokovic defeated him in five sets in 4 hours and 43 minutes, making it the longest semifinal in the history of Wimbledon men's singles. Starting the US Series, del Potro won the 2013 Citi Open in Washington DC, where he got a first-round bye, and then defeated Ryan Harrison, Bernard Tomic, and Kevin Anderson on his way to the quarterfinals, Tommy Haas in the semifinals, and won the final against John Isner in three sets. Before the final he didn't drop a set. This was his third title at the event and his second of the year. Del Potro reached the semifinals of Western & Southern Open where he won against Nikolay Davydenko, Feliciano López, in the quarterfinals Dmitry Tursunov, and faced Isner again, this time in the semifinals. He lost the match in three sets. Del Potro got to the second round of the US Open, after a four-set victory against Guillermo García-López, only to be upset by Lleyton Hewitt in five sets. At the 2013 Japan Open, Del Potro beat Marcos Baghdatis, Carlos Berlocq, Alexandr Dolgopolov, and Nicolas Almagro before beating third seed Milos Raonic to win his third title of the year. In October, Del Potro reached the final of the 2013 Shanghai Rolex Masters, defeating Philipp Kohlschreiber, Tommy Haas, Nicolás Almagro, and Rafael Nadal (for the first time since the semifinals of the 2009 US Open) en route, but eventually losing to defending champion Novak Djokovic in a third-set tiebreak. Later, he beat Roger Federer at the 2013 Swiss Indoors in the final, his fourth title of the year. However, lost to Federer at the 2013 BNP Paribas Masters and in a winner-take-all, round-robin clash in the 2013 ATP World Tour Finals. He finished the year with a 51–16 record, winning four titles overall and $4,294,039. Del Potro was named Argentina's Sportsman of the Year.