Shock exit for Li Na at Eastbourne

Li Na plays a forehand during her women's singles quarter-final match against Russia's Elena Vesnina in Eastbourne, southern England on June 20, 2013.

Second seed Li Na suffered a shocking straight sets defeat to Russia's Elena Vesnina in the quarter-finals of the Aegon International in Eastbourne.

Vesnina, the world number 36, needed one hour and 40 minutes to edge out the 2011 French Open champion 7-6 (7-4) 6-3.

The 31-year-old Li was competing at the pre-Wimbledon event at on the slick grass at Devonshire park for the fifth time and had never advanced past the second round.

She has now lost three of her four matches against Vesnina, five years her junior at age 26.

"Today was a little bit of surprise, the way she's playing," said Na. "I think sometimes I can play well, but sometimes I think I lose concentration on the court. That's why the match was going like up, down a little bit."

Elsewhere, Caroline Wozniacki set up a semi-final tie with Jamie Hampton after beating Ekaterina Makarova 4-6 6-0 6-3.

American Hampton advanced to the last four thanks to a 3-6 7-6 (7-1) 6-4 victory over Czech Republic's Lucie Safarova.