(Adds detail, second match)
LONDON, July 2 (Reuters) - The leading ladies had already exited stage left but the understudies kept the most volatile Wimbledon script bubbling along on Tuesday as Sabine Lisicki proved to be no one-hit wonder to reach the semi-finals.
A day after producing the shock of shocks at a tournament that has seen upsets galore by beating red-hot favourite Serena Williams, the smiling German overwhelmed Estonia's Kaia Kanepi 6-3 6-3 to reach the last four at Wimbledon for the second time.
There she will face Polish fourth seed Agnieszka Radwanska, runner-up last year and the highest-ranked player in an unfamiliar quarter-final line-up, who emerged victorious from an absorbing Centre Court battle with China's sixth seed Li Na.
A classic match-up between the powerful Li and the crafty Radwanska ended with the elastic-limbed Pole winning 7-6(5) 4-6 6-2 on her eighth match point
Radwanska saved four set points in the opener, squandered a 4-2 lead in the second as Li hit back, then, after an injury time-out to have strapping applied to her thigh, forged ahead under the closed roof, only to suffer an attack of nerves.
She double-faulted on one match point and on another she looped in a second serve that barely registered on the speed gun as Li threatened to begin the great escape and reach her first Wimbledon semi-final.
Radwanska finally sealed only her second win in a grand slam quarter-final in nine attempts when Li floated a backhand long.
A quarter-final line-up featuring eight players from eight nations and only two grand slam titles between them had prompted some scornful morning headlines.
However, the novelty factor added to the intrigue and fans flocking into the grounds reading up on the merits of Sloane Stephens and a Belgian nicknamed "Flipper" were provided with a refreshing variety of styles and blessed absence of grunting.
American Stephens, the 17th seed was up against unorthodox former finalist Marion Bartoli of France and Petra Kvitova faced Belgian outsider Kirsten Flipkens.
If Kvitova, the 2011 Wimbledon champion, loses, a new name will join the list of grand slam winners on Saturday.
So far giant-slayers have had short shelf lives at Wimbledon with Steve Darcis, Sergiy Stakhovsky and Michelle Larcher de Brito - who took out Rafa Nadal, Roger Federer and Maria Sharapova respectively - all failing to last another round.
Not so the grasscourt-loving Lisicki, who needed only 65 minutes to beat 46th-ranked Kanepi who a day earlier had ended the hopes of British teenager Laura Robson.
A semi-finalist in 2011 and quarter-finalist last year, the 23rd seed, who broke down in floods of tears after beating Williams but was calmer on Tuesday, is now only two wins away from becoming Germany's first grand slam champion since Steffi Graf won Wimbledon in 1996.
"I feel much fresher, fitter, better than two years ago," Lisicki, who lost to Sharapova in the 2011 semis, said.
"I was just as focused as yesterday because ... I knew it's going to be tough after yesterday to just keep the level up.
"But I think I did a very good job to go for my shots and play smart. It had to be a different game today." (Editing by Ed Osmond)