Hingis v Venus Saturday at WTA Rome

"In the beginning stages it wasn't so easy," Hingis said. "But she had a lot of tough matches in the previous round so maybe she was a little tired."

The No. 9-seeded Williams was forced to come back from a set down to defeat unseeded Jelena Jankovic 5-7, 6-4, 6-1, with the Serb choking an opportunity to serve out the second set at 5-4 before then collapsing in the third.

"She played really well, and it was difficult to play last night and then come out here again this afternoon," Williams said. "In the first set I made far too many mistakes."

Also into the semis were No. 7 seed Svetlana Kuznetsova who barely ended the run of homecountry Italian qualifier Romina Oprandi 6-4, 5-7, 7-6(4), and another Russian in No. 16 Dinara Safina who followed up her win over Kim Clijsters with a 6-1, 6-1 brutalization of No. 5-seeded countrywoman Elena Dementieva.

"She was hitting balls where I was not expecting," said Kuznetsova of Oprandi, who lost the first set after leading 5-2, then won the second set after trailing 1-4. "There were amazing drop shots and amazing lines."

Saturday's semifinal match-ups will be (9) Venus vs. Hingis (tied 10-10 with Venus winning their last three), and (7) Kuznetsova vs. (16) Safina (tied 2-2) in an all-Russian.

"I think the tournament is really open now," Safina said. "It's just a matter of who fights more and has more eagerness to win. It will be a great match against Kuzy. We know each other very well."