UPDATE 2-Tennis-Jankovic and Dementieva to meet in Moscow semi

(updates with Safina victory)

By Gennady Fyodorov

MOSCOW, Oct 10 (Reuters) - World number one Jelena Jankovic will face holder Elena Dementieva in the Kremlin Cup semi-finals after both overcame unseeded opponents on Friday.

The second semi will be an all-Russian affair between second seed Dinara Safina and number seven Vera Zvonareva.

Safina edged fifth-seeded compatriot Svetlana Kuznetsova 6-4 7-5 while Zvonareva beat teenage Slovak Dominika Cibulkova, who upset world number five Ana Ivanovic in the previous round, 7-5 6-4.

Dementieva was the first player to reach the last four, eliminating fellow Russian Nadia Petrova 6-4 4-6 7-6.

The third seed won the opening set and led 4-1 in the second and third before allowing her compatriot to rally each time. However, the Olympic champion held her nerve to clinch the tiebreak 8-6 after a match lasting nearly three hours.

Jankovic, making her Moscow debut, also had to use all her experience to beat Italian Flavia Pennetta 7-6 6-3.

Pennetta led 3-1 in the second set before the Serb, who replaced Serena Williams at the top of the WTA rankings on Monday, reeled off five successive games.