Madrid - Australia's Samantha Stosur and China's Li Na stormed into the women's quarter-finals at the Madrid Masters on Thursday.
Eighth seed Stosur stopped Swiss Patty Schnyder 7-6 (7/3) 6-2 while Li, the 13th seed at the Caja Magica, put out Alona Bondarenko of the Ukraine in the third round after a 6-3 6-4 win.
Stosur next faces a test against fourth seed Venus Williams, against whom she stands 0-3 from 2007 and 2008 meetings.
Li will play the winner from the unseeded pair of Israeli Shahar Peer and Spain's Arantxa Parra Santonja.
Stosur remains a huge force on the spring clay after winning 14 of her last 15 matches on the surface, taking the title last month at Charleston and playing the final in Stuttgart against Justine Henin.
The 26-year-old from the Gold Coast leads the WTA standings for clay wins in 2010 and will move up to a career-high seventh in the world rankings next Monday, just in time for the countdown to the French Open.
The 2009 Roland Garros semi-finalist will arrive in Paris as the highest-ranked Australian woman since Wendy Turnbull was classed fifth in February 1984.
"I've played well since Indian Wells (in March)," said Stosur, who was broken in the penultimate game by Schnyder, but immediately broke the Swiss back to claim victory.
"That form just translated over to the clay. I'm enjoying my tennis, it's just one of those things. Once you start winning it doesn't matter which surface it's on, it gives you confidence."
Stosur said that she got better as the contest with Schnyder went on.
"It was even in the first set with no breaks. The key was to hold serve.
"I was feeling very comfortable in the second set. Schnyder is a tricky lefty who likes to hit a loopy ball and play the angles. My strategy was not to give her too many chances.
"I'm feeling really good on the court and of course the confidence is growing."
Li took 90 minutes to go past the 26th-ranked Bondarenko, who now trails the Chinese 1-3 in their head-to-head series.
The number 13 seed poured pressure on her opponent, forcing the European to save 13 of 18 break points.
Li is donating all of her Madrid prize money to the China Foundation for Poverty Alleviation, which is helping with earthquake relief efforts in Yushu.
Singles Results (x denotes seeding):
Samantha Stosur (AUS x8) bt Patty Schnyder (SUI) 7-6 (7/3), 6-2
Li Na (CHN x13) bt Alona Bondarenko (UKR) 6-3, 6-4
Shahar Peer (ISR) bt Arantxa Parra Santonja (ESP) 7-5, 6-2
Jurgen Melzer (AUT) bt Fernando Verdasco (ESP x6) 7-5, 6-3