Australian Open champion Angelique Kerber has been dumped out of the first round at Roland Garros, losing 6-2 3-6 6-3 to Kiki Bertens.

Kerber stunned Serena Williams to clinch the title in Melbourne in January, but emulated Li Na and Stan Wawrinka by following up her maiden grand slam crown with a first-round exit at the French Open.

The German had an outside opportunity of becoming world number one in Paris, but it was the 58th-ranked Bertens who made the better start, breaking twice to clinch the first set.

Kerber came back from the brink of elimination to see off Misaki Doi in the first round at the Australian Open, and she served out the second set to raise hopes of another fightback.

However, Bertens - forced to retire after going ahead against Kerber in Miami this year - raced into a 3-0 lead in the deciding set.

Third seed Kerber left Court Philippe Chatrier to receive treatment on an injured shoulder and, after holding the first service game upon her return, blew two break points as she fell 4-1 behind.

Kerber battled to keep her tournament alive, saving two match points, but she let another break point pass her by before a drop shot fell short to hand Bertens victory.