DOHA, Qatar - Venus Williams beat Agnieszka Radwanska for the second time this year to line up two-time champion Victoria Azarenka in the Qatar Open semifinals on Thursday.

Williams, who beat Radwanska to reach the Australian Open quarterfinals last month, won 6-4, 1-6, 6-3, the third time in four days she's gone the distance.

Azarenka, the 2012 and 2013 champ who received a wild-card entry, beat third-seeded Caroline Wozniacki 6-3, 6-1 in another repeat result from the Australian Open.

Meanwhile, top-seeded Petra Kvitova was ousted by Carla Suarez Navarro of Spain 3-6, 6-0, 6-3, for the second time in two weeks. Suarez Navarro also beat Kvitova last week in the Dubai third round.

The Spaniard's semifinal opponent will be Lucie Safarova, the Czech who dispatched sixth-seeded Andrea Petkovic of Germany 6-2, 6-1.

Williams started her quarterfinal with a break, wobbled during the second set, and was quick to recoup in the decider, in which fourth-seeded Radwanska mounted a late challenge. Williams sealed her first semifinal in Doha with a forehand winner down the line.

"I just tried to stay focused because she wasn't going to let up," Williams said after the 2-hour, 16-minute match.

Williams has won all four of her previous matches against Azarenka, but was expecting to endure another long day.

"Every match (this week) has been three sets, so it's been really challenging," Williams said. "No one gives you a point, you have to fight, fight, fight for each point, and I guess it'll be more of that tomorrow."

Meanwhile, Azarenka fired 26 winners against Wozniacki in a match of former No. 1s.