China's Li Na missed her chance for a semi-final spot at the ATP-WTA Eastbourne International on a muggy Thursday as the second seed lost to Russian Elena Vesnina 7-6 (7/4), 6-3.
Vesnina, winner along with compatriot Ekaterina Makarova of the Roland Garros doubles title less than a fortnight ago, carried confidence from her grand slam trophy onto the slick grass at Devonshire park as she beat her first top 10 opponent in two years.
Australian Open finalist Li was competing at the pre-Wimbledon event 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 Li. "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.
"I would have liked to have some more matches, but I'm looking forward to Wimbledon. Tennis is in the mind and my mind can go somewhere else. That's my problem right now."
After play started around an hour late due to mist in the air which made the grass too slippery to play on, Li began with a break of the Russian but was pegged back for 2-2 before Vesnina took the set into a tiebreaker and won it on her first set point after 55 minutes.
In the second set, double-faults spelled doom for Li, who twice was broken on her misfiring serve as Vesnina earned a 5-3 lead after losing a break in the seventh game.
Vesnina then served out the victory to advance into her first career semi-final on grass.
"I'm really excited about this," said Vesnina. "I'm very happy to win, It was a tough match, especially against Li Na. I like to play on grass, I feel it suits my game. I'm really enjoying the surface this week."
The world number 36 will next face Yanina Wickmayer, who beat sixth seed Maria Kirilenko 6-2, 1-6, 7-5.
Fifth seed Caroline Wozniacki won a two-hour struggle between former champions as she defeated Makarova 4-6, 6-0, 6-3, her sixth win without a loss over the Russian.
"I'm feeling pretty good, I feel like I have been playing really good tennis. I'm really pleased with it. I like the grass and I think it really suits my game.
"She came out playing aggressively, playing well. But I found my game to make it a good match."
Wozniacki stared slowly, losing the opening set but running off nine games in a row to claim the second and reach 3-0 in the third.
She stuttered by dropping serve at 4-2 but broke back to love as she moved onto victory.
The Dane faces 41st-ranked qualifier Jamie Hampton, who beat Lucie Safarova 3-6, 7-6 (7/1), 6-4 to become the first American to go this far at Eastbourne since Jennifer Capriati a decade ago.
Hampton's victory was a repeat of her success against Safarova in the French Open first round.
In the men's event, French second seed Gilles Simon outlasted Australian Bernard Tomic 7-6 (10/8), 6-3 to set up a semi-final clash with 2011 champion and Andreas Seppi. The seventh seed reached his third straight semi-final here, beating Radek Stepanek 6-4, 6-2.
Ivan Dodig continued his giant-killing act a day after upsetting top seed Milos Raonic.
The unseeded Croatian took down Italian eighth seed Fabio Fognini 6-3, 6-2 with a clinical serving display as he played in his third career grass quarter-final.
Meanwhile, Wimbledon quarter-finalist Feliciano Lopez beat good friend and compatriot Fernando Verdasco 6-4, 7-6 (8-6) with Verdasco complaining of a slick court. His pleas to halt the match on safety conditions went unanswered by officials.