The Danish tennis player Caroline Wozniacki has secured the year-end world number one ranking with a three-set victory over Francesca Schiavone at the WTA Championships in Doha.
Wozniacki, the first Dane to become a number one tennis player, needed two wins at the $6 million season-ending tournament in the Qatari capital to ensure Russia's Vera Zvonareva could not snatch the top spot.
After blowing away Elena Dementieva in her Maroon Group opener, Wozniacki suffered a shock defeat by Sam Stosur to give Zvonareva hope.
However, the 20-year-old from Odense made no mistake against French Open champion Schiavone.
The win guarantees Wozniacki a spot in this weekend's semi-finals while Italy's Schiavone cannot make the final four.
The Dane, the youngest player in the field, has already won six titles this season and claimed the number one ranking earlier this month after reaching the quarter-finals of the China Open, which she went on to win.
Still, the Russian had the consolation of qualifying for the semi-finals without even hitting a ball today, thanks to Kim Clijsters's three-set win over Victoria Azarenka.
Clijsters's victory put both her and Zvonareva through with two wins apiece, meaning two of the three remaining round-robin matches will be dead rubbers.
Only the Clijsters-Zvonareva clash will have an impact on the tournament, with the winner to top the White Group undefeated.
In the semis, Stosur will play the loser of the Clijsters-Zvonareva match for a place in the final, with Wozniacki to face the winner.