BUENOS AIRES (AFP) - Defending champion Rafael Nadal suffered another setback on Saturday when he squandered a match point before losing 6-4, 4-6, 7-6 (7/4) to Austria's Dominic Thiem in the Argentina Open semi-finals.
Top seed Nadal finally wilted in the 32-degree heat in Buenos Aires after two hours and 50 minutes on court against Thiem, the world No. 19, who goes on to face either David Ferrer or Nicolas Almagro in Sunday's final.
Nadal, playing his first tournament since his shock first round exit at the Australian Open, dropped serve in the ninth game of the opener to allow the 22-year-old Austrian to serve out for a one-set lead.
The 29-year-old Spaniard fought off a break point in the seventh game of the second as the big-hitting Thiem threatened to run away with the contest.
But the 14-time major winner made the most of his lifeline to break in the 10th game to level the semi-final.
Thiem, who once trained for his matches by carrying tree trunks on his back to beef up his physique, nipped ahead for 2-0 in the decider.
But back came Nadal to level at 2-2 before Thiem saved a match point in the 10th game.
In the tiebreak, however, it was Thiem who proved the stronger, stretching to a 6/1 lead.
Nadal saved three match points but the Austrian held his nerve to give himself a shot at a fourth career title on Sunday.