Intro:

Samantha Stosur beat Venus Williams 6-3 4-6 6-3 at Charleston on Friday to set up a final four meeting against her sister, Serena Williams.

Lucie Safarova is also through to the semi-finals after she dispatched Vera Zvonareva 6-3 6-3. She will play Polona Hercog for a place in the final.

Script:

Charleston was Venus Williams' first clay tournament in two years, but she'd made it through to the quarter-finals, up against Samantha Stosur on Friday.

Williams has been blighted by an autoimmune disease and was slow to get started, losing the first set to the Australian, 6-3.

However she fought back to take the second 6-4, with some typical power.

But there was no denying Stosur as she cruised through the decider 6-3.

That victory sets her up a final four show down against Williams' sister Serena.

SOUNDBITE: (English) Samantha Stosur:

"I've never been able to beat Venus, she's beaten me pretty easily sometimes too. I guess today it was just another good challenge for me and tried to just play well and keep doing what I wanted to be doing and play aggressive. If I was going to lose, then I was going to lose that way, but thankfully it came off."

Meanwhile ninth seed Lucie Safarova had no trouble dispatching number four Vera Zvonareva in straight sets.

SOUNDBITE: (English) Lucie Safarova:

"It was a really great match. I feel very good on the court here in Charleston. I grew up on clay, I like clay so it's nice to be back on clay for me. Today was everything working, I was running very well, serving very well and pushing Vera, so it was amazing for me."

She'll play Polona Hercog in the semi-finals.