Wildcard Mona Barthel claimed her second scalp at Stuttgart's claycourt WTA tournament yesterday to reach the last eight after she knocked out seventh seed Marion Bartoli.

The 21-year-old German, who blasted down 11 aces to out-muscle former world No. 1 Ana Ivanovic of Serbia on Wednesday in straight sets, needed just 71 minutes to beat France's Bartoli 6-3, 6-1 as she hit a further seven aces.

In today's quarterfinals, Barthel, ranked 35th in the world, will now face either current world No. 1 Victoria Azarenka of Belarus or Germany's Andrea Petkovic.

French Open winner Li Na also advanced by beating Akgul Amanmuradova of Uzbekistan 6-4, 6-4 in their second round tie. The Chinese eighth seed will play Poland's Agnieszka Radwanska next.

Likewise, Wimbledon champion Petra Kvitova of the Czech Republic had few problems in her 6-2, 6-2 win over Italy's Francesca Schiavone to set up a last-eight match against either former world No. 1 Caroline Wozniacki of Denmark or Germany's Angelique Kerber.

In Barcelona, Andy Murray crushed Colombia's Santiago Giraldo in a powerful 6-1, 6-2 display yesterday to set up a quarterfinal showdown with Milos Raonic at the Barcelona Open.

Second seed Murray, a quarterfinalist a week ago in Monte Carlo, reached the last eight again as he prepares for the French Open next month.

Murray and No. 25 Raonic, who put out two-time semifinalist Nicolas Almagro 6-3, 6-3, will finally clash in a match which should have been played in March at Miami had the Canadian not suffered an injury and been forced to withdraw to give Murray the walkover third-round win.

Murray's win was his 25th of the season against five defeats.

Top seeded Rafael Nadal, who has won six of the last seven editions of the tournament, also eased into the quarterfinals after the Spaniard eased past Colombian Robert Farah 6-2, 6-3.

Spanish seventh seed Feliciano Lopez beat Finn Jarkko Nieminen 6-3, 6-1 while Japan's Kei Nishikori continued his own progress, with the eighth seed defeating Spaniard Albert Ramos 7-6 (2), 6-3.