Del Potro won one match at the Masters Cup, against Tsonga, but lost his other two matches against the higher-ranked Djokovic and Davydenko, meaning that he exited the tournament in the round-robin stage. This was his last event of the year on the ATP Tour. He went on to lose one match in the Davis Cup final, against López, as his team succumbed to a 3–1 loss against Spain. He withdrew from his second match due to a thigh injury and was replaced by José Acasuso. Nonetheless, del Potro enjoyed a successful season; winning four titles and finishing 2008 as the youngest player in the top 10, top-ranked Argentine, and highest-ranked South American.