BERLIN, April 27 (Xinhua) -- China's Grand Slam winner Li Na was crashed out of the quarterfinals of the Stuttgart WTA clay court tournament on Friday by Polish Agnieszka Radwanska.

The 2011 French Open winner was beaten 3-6, 6-2, 6-3 by the fourth seed Radwanska, who had played some strong returns and drop shots since the second set.

"I am enjoying my tennis and just trying everything at the moment," said the 23-year-old Pole, ranked fourth in the world and who claimed her ninth tour win at Miami recently.

Radwanska will next play the winner between world No. 1 Victoria Azarenka and wildcard Mona Barthel, who faces each other later on Friday.

Also on Friday, world No. 2 Maria Sharapova takes on the fifth seed and U.S. Open winner Samantha Stosur, while Wimbledon champion Petra Kvitova faces Angelique Kerber.