Unseeded Mariano Puerta won the battle of the Argentines when he beat Guillermo Canas 6-2, 3-6, 1-6, 6-3, 6-4 to reach the French Open semi-finals on Wednesday.
Puerta, who was appearing in his first grand slam quarter-final, reeled off the first five games of the match.
Ninth seed Canas battled back to lead two sets to one but as the rallies grew longer and more punishing, Puerta's greater firepower began to pay dividends and he levelled the match.
Canas needed treatment on his feet early in the decider but it did not affect his movement as he scampered all over the court to stay in the rallies.
After grabbing a crucial service break midway through the set Puerta reached double match point at 5-4, only to be denied by two spectacular passing shots from his opponent.
However the 26-year-old left hander held his nerve to clinch victory at the third attempt when Canas netted a forehand after three hours 35 minutes.
For Puerta, who will play either Spain's Tommy Robredo or Russian Nikolay Davydenko in the semi-finals, his run at Roland Garros caps a remarkable transformation after he was suspended for nine months when he tested positive for the banned substance clenbuterol.
He returned last July with a ranking of 440 and spent the rest of the year playing on the second-tier Challenger Circuit.
This year he has been a consistent performer on clay, winning the title in Casablanca and reaching the final in his home city of Buenos Aires.
