Li Na of China reaches to return a forehand to Angelique Kerber of Germany during their Women's singles match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 14, 2012. [Photo/China Daily]

French Open champion Li Na exited the WTA Indian Wells event Wednesday, losing 6-4, 6-2 in the quarter-finals to Angelique Kerber of Germany.

Kerber broke Li twice in the opening set and three times in the second, completing her first win over the Chinese in four career meetings when her opponent hit a backhand service return long.

"I was a little bit surprised. She has unbelievable defence," said Li, the eighth seed. "Sometimes I think I can win the point, but she just tried to get the ball back all the time. All I can say is today was very tough for me."

Li, who missed a month with the back injury, won just nine of 22 points on her second serve.

Kerber won 65 percent of her first serve points and saved seven of nine break points in the 83 minute match in front of a crowd of about 2,500.

"This is very special," said the 24-year-old Kerber. "She's a great player and I had nothing to lose tonight.

Kerber will next face world number one Victoria Azarenka, who stormed into the last four of the tournament with a ruthless 6-0 6-2 demolition of Agnieszka Radwanska.

Australian Open champion Azarenka outplayed her Polish opponent from the baseline, coasting through the opening set in 25 minutes and racing to a 5-0 lead in the second before being surprisingly broken.

Though fifth-seed Radwanska then held serve for the first time in the match, Azarenka served out to clinch a one-sided victory in just over an hour when her opponent netted a forehand.

"I was really impressed with the way I played today," a beaming Azarenka said in a courtside interview after improving her record to 9-3 against Radwanska. "I didn't expect to win that way. I'm proud how I fought hard and played winning tennis."

Victoria Azarenka of Belarus serves to Agnieszka Radwanska of Poland during their women's singles match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 14, 2012. [Photo/China Daily]