MOSCOW -- Samantha Stosur will face doubles partner Svetlana Kuznetsova in the semifinals of the Kremlin Cup after both players won in straight sets Friday.
Stosur extended her unbeaten run to eight matches by defeating Ana Ivanovic 7-5, 6-4, while Kuznetsova beat second-seeded Roberta Vinci 6-2, 6-3.
Also, defending men's champion Andreas Seppi of Italy made it into his fifth semifinal of the season after Edouard Roger-Vasselin retired with a neck strain while trailing 5-2.
In a rematch of last year's three-set semifinal match between former Grand Slam champions, Ivanovic took a 3-0 lead but Stosur broke back twice to win the opener. An early break in the second set was enough for the Australian to defeat the former top-ranked Ivanovic for the second straight year.
"Probably having a match won here last year, I certainly had a few things in my head that I wanted to try to do today against her," Stosur said. "And right from the start it was kind of working and from that my confidence kind of built, and I was able to keep going and play well till the end."
Last Sunday, Stosur won the fifth title of her career in Osaka, Japan, while Ivanovic lost in the Linz final.
Kuznetsova, a two-time Grand Slam champion, broke twice in the first set. But Vinci offered more resistance in the second, trading breaks twice before the Russian took a 4-2 lead.
"Today I played really well in the first set with some slight mistakes in the second, which I managed to overcome," Kuznetsova said. "I hope I'll be able to boost my performance in the next matches as well."
The Russian will be playing in her first semifinal this season and her first at a home event since she lost to Serena Williams in 2007.
In the men's tournament, Roger-Vasselin strained his neck during the warm-up and had it treated after the first game.
"From his first service game and down in the match he couldn't serve normally," Seppi said. "I would never like to win like this but sometimes it happens."
Seppi will next play Mikhail Kukushkin, who beat Andrey Golubev 6-4, 7-6 (4).
Croatian veteran Ivo Karlovic advanced to his second semifinal of the season by winning eight consecutive games and landing 11 aces to rout Russian teenager Karen Khachanov 6-4, 6-0.