IF Novak Djokovic entered the French Open with plenty of question marks hanging over his form he departs Paris still searching for answers after suffering his first straight-set Grand Slam defeat since the 2013 Wimbledon final.

Dominic Thiem crushed Roland Garros’ defending champion 7-6 (7-5), 6-3, 6-0 in the quarterfinals on a sunny, blustery Wednesday, a result that means the Serb will also tumble out of the top two in the rankings for the first time since early 2011.

Thiem must now upend familiar foe Rafael Nadal — who progressed when Pablo Carreno Busta retired while trailing 6-2, 2-0 — to make a maiden Grand Slam final.

World No. 1 Andy Murray and 2015 winner Stan Wawrinka will square off in the semifinals for the second straight year after the Scot eliminated Japan’s Kei Nishikori 2-6, 6-1, 7-6 (7-0), 6-1 and the Swiss eased past Croatia’s Marin Cilic 6-3, 6-3, 6-1.

Meanwhile, there was drama in the women’s quarterfinals, as third-seed Simona Halep rallied from a 5-1 second-set deficit and saved a match point to overcome fifth-seed Elina Svitolina 3-6, 7-6 (8-6), 6-0.

Karolina Pliskova, the second seed, claimed a marathon first set on the way to beating the last French player remaining in singles, Caroline Garcia, 7-6 (7-3), 6-4.

If Pliskova ousts Halep, the Czech will replace Angelique Kerber as the women’s No. 1.

That Thiem ousted Djokovic wasn’t a huge surprise — after all the seventh-ranked Austrian trails only Nadal in match wins in 2017 and is tied for first with the Spaniard in clay-court victories this season.

But the manner in which Djokovic crumbled in the third set will be particularly worrying for his fans.

Only 12 months ago he put the exclamation mark on one of the most dominant spells in tennis history, beating Murray in the final in Paris to become the first man in 47 years to claim four consecutive majors.

(SD-Agencies)