Top seed Carlos Moya was beaten by unseeded Argentine Mariano Puerta in the straight sets in the quarter-finals of the Buenos Aires Open on Friday.
Puerta, who has not won an ATP singles title since Bogota in 2000, beat Moya 7-6, 6-3 to rapturous applause from the 5,000 crowd, ending the Spaniard's dream of winning the tournament for the third time.
Moya, who went through his first two matches without dropping a set, won the first of his 18 singles titles in Buenos Aires 10 years ago and repeated his win in 2003.
Earlier, Alberto Martin became the first player into the semi-finals when he came from behind to beat fellow Spaniard Felix Mantilla 5-7, 6-4, 7-6.
Martin will meet the winner of the match between second seed Gaston Gaudio -- aiming to win his second successive tournament after last week's victory in Vina del Mar -- and 18-year-old Spaniard Rafael Nadal, who were playing later on Friday.
