Nadia Petrova, who is seeking back-to-back WTA Tour titles, will play her doubles partner Anna-Lena Groenefeld in the semi-finals of the Family Circle Cup.

Russian second seed Petrova advanced Friday with a commanding 6-2, 6-0 victory over unseeded Colombian Catalina Castano to set up a clash with the in-form sixth seed Groenefeld.

Hard-serving German Groenefeld survived 13 double faults to get by fourth seed and 2004 U.S. Open champion Svetlana Kuznetsova 6-3, 7-6 (7-4).

Top seed and defending champion Justine Henin-Hardenne will play Patty Schnyder in the other semi-final.

Henin-Hardenne defeated Russia's Dinara Safina 6-4, 6-1 to give her a 14-0 career record on Charleston's green clay. Schnyder, 0-6 against Henin-Hardenne, eliminated France's Nathalie Dechy 6-0, 6-3.

Petrova needed only 61 minutes to oust Castano.

"I really dominated my games," said Petrova, who won last week at Amelia Island.

"I had everything in my hands. She played a few good points but I must say I just didn't let her play the tennis she likes. She likes the heavy balls, to move a lot on the court. I just tried to make the points as short as possible."

Petrova is 3-1 against Gronefeld in singles competition and the two have not met in 2006. They won their doubles match Friday, defeating Liezel Huber and Kveta Peschke to advance to the semi-finals.

Groenefeld has won 14 of her last 17 matches on tour and was glad to get through despite the glitches.

"I hit a lot of double faults," she said, "but overall I think I played very aggressive, hit a lot of good shots, winners. I was always inside the court and not letting her dictate. That I think was the key."