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.