Agence France Presse
The defeat was Sharapova’s first at the venue after sweeping to the title in 2012, 2013 and 2014 on the back of 13 successive wins. It also means the French Open champion will lose her World No. 2 ranking to Simona Halep next week. Kerber will face Sharapova’s Russian compatriot Ekaterina Makarova in the quarterfinals.
Sharapova, who skipped Russia’s Fed Cup semifinal win over Germany with a leg injury last weekend, was on course for a comfortable win at one stage, leading by a set and 5-4.
But left-handed Kerber won three games in a row to sneak the second set 7-5 before eventually taking victory after two hours and 27 minutes.
World No. 4 Petra Kvitova also suffered a shock defeat, beaten in straight sets by unseeded American Madison Brengle. The US girl ran out a 6-3, 7-6 (7-2) winner as Kvitova failed to make it past the second round in her first tournament since February.
The unseeded American, who reached the last 16 at the Australian Open, will next face France’s Caroline Garcia who put out Carina Witthoeft of Germany 7-6 (7-4), 6-2.
Fourth seed Caroline Wozniacki defeated Czech veteran Lucie Safarova 7-6 (7-5), 6-1 in her first outing on clay this year.