Svetlana Kuznetsova of Russia celebrates her victory in Doha on Friday. (AP)

Doha: Serbia’s Jelena Jankovic crushed a leg-weary Caroline Wozniacki 6-2, 6-2 to reach the semi-finals of the WTA Championships on Friday.

Svetlana Kuznetsova of Russia also won, beating compatriot Elena Dementieva 6-3, 6-2. Kuznetsova’s win also took Venus Williams to the semi-finals. Sister Serena reached the last four stage Thursday.

Jankovic had spent just 95 minutes on court here in her first two matches compared to the nearly six hours of sweat and toil put in by the 19-year-old Wozniacki, and it showed in a one-sided contest.

From 2-2 in the first set Wozniacki, who collapsed in agony with cramp near the end of her brutal victory against Vera Zvonareva 24 hours earlier, simply ran out of gas.

She managed to stop the rot when she broke back once late in the second set but there was no way back for the US Open finalist.

Jankovic, who was ranked No. 1 in the world earlier this year, seemed ready to pack her bags and go home after losing to Azarenka in the season-ending tournament’s opening match on Tuesday, so disheartened she was with her form.

In her second match of the $4.5m showpiece event she got a major stroke of luck when Russia’s Dinara Safina pulled out after 12 minutes with a back injury. The cards continued to fall in her favour on Friday as Wozniacki clearly had not recovered from the punishment her body had taken in the previous two days in her three-set victories against Azarenka and Zvonareva.

“I didn’t really know what to expect from her,” a sweat-soaked Jankovic said on court.“I saw what happened to her Thursday but I just concentrated on trying to win the match and get through to the semi-finals.

(Reuters)