PARIS: Bianca Andreescu became the highest women's seed to fall at the French Open so far as she lost a three-hour marathon match against Timara Zidansek in the first round on Monday.

The former US Open champion, seeded sixth, went down 6-7(1) 7-6(2) 9-7 to the Slovenian.

Canadian Andreescu, 20, served for the match at 5-4 in the deciding set but Zidansek broke back before missing a match point of her own in a gripping finale.

Andreescu found herself in trouble again serving at 7-8 and this time was unable to dig her way out of trouble with world number 85 Zidansek winning in three hours and 20 minutes.

While on paper it was a shock, Andreescu was playing at only her third Tour-level claycourt tournament and her lack of experience on the surface ultimately proved decisive.

The women's draw lost another big name when former French Open semi-finalist Kiki Bertens fell at the first hurdle, losing 6-1 3-6 6-4 to another Slovenian Polona Hercog.

Marketa Vondrousova, the 2019 runner-up who is seeded 20th this year, managed to avoid an early exit, battling back from a set down to beat Kaia Kanepi 4-6 6-3 6-0.