Nadal slips to Thiem loss, Almagro finally beats Ferrer

The defending champion was one point away from victory at 5-4 in the third on Thiem's serve but the Austrian rallied, forcing a tiebreak which he controlled from the off to take the contest 6-4 4-6 7-6(4).

"It was an amazing match for me," world number 19 Thiem said.

"It was very tight from the beginning. It's special to play against the big guys, and to beat one is a dream come true. In the third set, Nadal really stepped up but I was able to counter-attack and play incredible shots."

Spaniard Nadal's loss was another early season setback for the 14-times grand slam champion who was dumped out of the first round of the Australian Open by unseeded compatriot Fernando Verdasco, one of the biggest shocks of the tournament.

Thiem will face another Spaniard in the final after Nicolas Almagro beat second seed and former champion David Ferrer 6-4 7-5.

It was Almagro's first win over the world number six at the 16th time of asking and came after Ferrer had to finish his rain-delayed quarter-final earlier on Saturday.

"This is the reward for many months of hard work, but there's no time to celebrate," Almagro said. "I have to focus on tomorrow's match and hopefully I can play at the same level."

Nadal will head to Brazil for next week's Rio Open where he will attempt again to reach his 100th elite final.