Dominic Thiem claimed a landmark win as he upset Rafael Nadal in Buenos Aires

Talented youngster Dominic Thiem is through to the final of the Argentina Open after stunning defending champion Rafael Nadal.

The 22-year-old Thiem is the youngest player in the world top 20 and secured a landmark victory, saving a match point before going on to win 6-4 4-6 7-6 (7-4).

Nadal has been virtually unbeatable on clay during his distinguished career but world No 19 Thiem broke twice to take the opening set.

However, Nadal responded, claiming the only break of the second set in the 10th game to level the match.

But Thiem showed his mettle in the decider, letting an early break slip away, but then saving a match point at 4-5 with a gutsy forehand, before taking advantage of some Nadal errors to race into a 6-1 lead in the decisive tie-break.

Nadal saved three match points but the fifth-seeded Austrian held his nerve to give himself a shot at a fourth career title on Sunday, in what will be his fifth final, all of which have been on clay.

It was a chastening defeat for Nadal, who hinted at a return to top form towards the end of 2015 and then reached the final in Doha at the start of this year.

However, he was comfortably defeated there by Novak Djokovic and then lost to Fernando Verdasco in the first round of the Australian Open.

"It was a tough match," he said. "I had a chance to win and missed it but Thiem played well.

"I'm not worried. I just lacked consistency and need to make fewer unforced errors, but that's nothing."

The match was played in 32C heat and Nadal can expect more of the same when he plays in Rio next week.

"I struggled a bit to adapt to the extreme conditions here," he said. "I felt more tired than usual.

"I know that in Rio de Janeiro it's not going to be better, so I must continue to adapt."

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