MOSCOW : World number one Jelena Jankovic of Serbia has set up a Kremlin Cup semi-final showdown with defending champion Elena Dementieva after beating Italian Flavia Penetta in the quarters.

Jankovic, the top seed in the women's draw of the 2.4-million-dollar joint ATP and WTA event, was a 7-6 (8/6), 6-3 winner over Penetta, recording her fifth victory over the 26-year-old Italian in as many meetings.

The duo traded breaks throughout the opening set, forcing a tiebreak, which Jankovic, who is seeking her season's fourth crown, won 8/6 for a one-set lead.

The Italian started the second set with an immediate break for a 3-1 advantage but Jankovic moved up a gear to take five consecutive games to win the set and the match.

"It was a tough match for me today and I didn't play it the way I wanted to," said the 23-year-old Jankovic, who had received on-court treatment for a sore back in Thursday's play.

"I felt a bit tired and was struggling myself all the way."

Jankovic will now face defending champion and third seed Dementieva, who advanced to the semis with a tough 6-4, 4-6, 7-6 (8/6) victory over compatriot Nadia Petrova.

"It wasn't easy match. It was emotionally tough," Dementieva said. "We met Nadia at Wimbledon this year and it was also a very emotional game.

"Today I missed plenty of chances. It's not easy to play at your best when emotions meddle in."

The tournament's second seed, Dinara Safina of Russia, beat her fifth seeded compatriot Svetlana Kuznetsova 6-4, 7-5 to record her seventh win in their 11th head-to-head clash.

In the semi-finals, Safina will meet another Russian, Vera Zvonareva, the event's seventh seed who completed the last-four line-up by beating Slovak Dominika Cibulkova 7-5, 6-4 in their first ever meeting.

- AFP /ls