D'Italia Junior tournaments. Del Potro reached his first final of the ITF Junior Circuit on 11 January 2005, the "Copa del Cafe (Coffee Bowl)" Junior ITF Tournament in Costa Rica, where he lost to Robin Haase in three sets. He was involved in a dispute with the umpire during this match, who decided to stop play because of rain, which del Potro believed favoured Haase. Because of the rain delays, the final set had to be played indoors; this was the first time the indoor courts had been used in the 44-year history of the youth tournament. At the age of 16, del Potro reached his first senior singles final at the Futures tournament in Berimbau Naucalpan, Mexico, where he lost to Darko Mađarovski. He then went on to win consecutive titles at two Future ITF Circuit events in Santiago, Chile, including the 26th International Junior tournament. In the first tournament, he beat Jorge Aguilar, and in the second, he did not drop a set in the whole tournament and defeated Thiago Alves in the final, a player ranked more than 400 places higher at the time. He won his third title in his home country by defeating Damián Patriarca, who forfeited the match, at the ITF Circuit event in Buenos Aires. Del Potro turned professional after the Italy F17 event in Bassano, and in his first professional tournament, the Lines Trophy in Reggio Emilia, he reached the semifinals, where he lost to countryman Martín Vassallo Argüello in three sets. Two tournaments later, he reached the final of the Credicard Citi MasterCard Tennis Cup in Campos do Jordão, Brazil, where he lost to André Sá in straight sets. After turning 17, he won the Montevideo Challenger by defeating Boris Pašanski in the final in three sets. That same year, he failed in his first attempt to qualify for his first Grand Slam, at the US Open, losing in the first round to Paraguayan Ramón Delgado. Throughout 2005, del Potro jumped over 900 positions to finish with a world ranking of no. 157, largely due to winning three Futures tournaments. He was the youngest player to finish in the year-end top 200. 2006: Top 100 In February, del Potro played his first ATP tour event in Viña del Mar, where he defeated Albert Portas, before losing to Fernando González in the second round. Later, seeded seventh, he won the Copa Club