Australian Open champion Angelique Kerber has fallen at the first hurdle at the French Open, losing in three sets to Kiki Bertens on Tuesday.
Bertens managed to come through the clash with a 6-2 3-6 6-3 victory on the clay court in Paris.
The world number 58 went an early break up in the first set and held on to the momentum as she extended her lead further with another break of serve.
Kerber failed to create a single break point in the opening set, but she put up a fight in the second as she earned a double break to level things up.
The German, whose best finish at Roland Garros is the quarter-finals, suffered a blow as she lost her opening service game in the third and final set.
Bertens managed to save three break points before wrapping up the set and sealing a place in the second round.