The Serbian second seed was easily beaten 7-6, 6-3, 6-0 in Paris and the defeat will see Djokovic drop out of the world's top two for the first time in six years.

It is the first time Djokovic has lost a set to love at a Grand Slam since the 2005 US Open.

"I didn't play a different game style," Thiem said.

"I just had a positive win-error statistic, and that was never the case against him before.

"I could easily have lost the close first set, and it was the key for my first victory against him to then have a good start to the second set as well.

"It's great for me to be in the semi-finals again."

The Austrian will now play Spain's Rafael Nadal in the last four of the clay court Grand Slam.

Nadal reached the semi-finals after fellow Spaniard Pablo Carreno Busta withdrew from their match with an abdominal injury.

Fourth seed Nadal, who is aiming to win a record 10th title at the French Open, took the opening set 6-2 and was 2-0 up in the second when his compatriot brought the match to a premature end.

Elsewhere in the men's singles draw, Britain's Andy Murray came through a hard-hitting contest with Japan's Kei Nishikori.

The world number one was outclassed in the first set and lost it 6-2.

However, a swift response saw Murray take the second 6-2 before he went ahead with a 7-0 tiebreak victory in the third.

From the moment he went in front, the double Olympic champion looked at ease and went on to comfortably take the fourth set 6-1.

The Scot will now play Switzerland's Stan Wawrinka in a repeat of last year's semi-final.

The 2015 French Open champion coasted to a 6-3, 6-3, 6-1 win over Croatia's Marin Cilic today.

Murray got the better of Wawrinka last year, winning  6-4, 6-2, 4-6, 6-2.

In the women's competition, Romania's Simona Halep come from behind to defeat Ukraine's Elina Svitolina 3-6, 7-6, 6-0 in the quarter-finals.

The tournament's third seed was on the brink of elimination after finding herself 5-1 down in the second. 

Halep, however, went on to win five consecutive games before saving a match point to take it to a decider, where she coasted to victory.

She will play Karolína Plíšková of the Czech Republic in the last four.

The world number three beat Caroline Garcia 7-6, 6-4 to eliminate the last French hope in both the men's and women's competitions.

Pliskova will replace Germany's Angelique Kerber as the new world number one if she beats Halep to make the final.

The other women's semi-final will see unseeded Latvian Jelena Ostapenko take on Switzerland's Timea Bacsinszky.