Caroline Wozniacki rolled up her sleeves and battled back from a set down to defeat Francesca Schiavone of Italy 3-6, 6-1, 6-1 at the WTA Championships on Thursday, sewing up the year-end world number one ranking.
Also in the Maroon Group, Australian Samantha Stosur lost 4-6, 6-4, 7-6 to Russian Elena Dementieva but by winning the first set booked her place in the last four alongside Wozniacki.
Belgium's Kim Clijsters also beat Victoria Azarenka of Belarus 6-4, 5-7, 6-1 to advance to the semi-finals from the White Group along with Vera Zvonareva.
Wozniacki needed two wins at the $4.55 million tournament in the Qatari capital to ensure she could not be caught at the top of the rankings by Russian Zvonareva.
After blowing away Dementieva in her group opener, the Dane suffered a shock defeat to Stosur on Wednesday to give Zvonareva hope. However, the 20-year-old made no mistake against Schiavone.
"Francesca was playing really good in the first set and I didn't have too many chances to break her," said Wozniacki in a court-side interview.
"I just hung in there and kept my focus, tried to get a little more aggressive and not let her dictate the game in the second and third."
Wozniacki was delighted to finish the year as the world's top player.
"That's something I've dreamed about since I was a little girl," she beamed. "I'm really happy and proud of what I've achieved this year."
BRAVE STAND
With maroon and white Qatari flags fluttering above the Khalifa Tennis Complex, conditions were much more comfortable for the players than the oppressive humidity of the first two days.
Schiavone came out firing on all cylinders and caught the Dane off guard, tearing around the court after every ball, living and dying every point.
The Italian raced into a 4-1 lead, prompting Wozniacki's father and coach Piotr to come out on court for a pep talk, before thumping a trio of aces at 5-3 to reach set point and unleashing a backhand winner down the line to draw first blood.
That would be as good as it would get for the 30-year-old French Open champion as Wozniacki grabbed the match by the scruff of the neck and never let go.
The Dane streaked into a 3-0 lead as Schiavone began to unravel with a string of unforced errors and emotional outbursts into the Doha night sky.
After taking the second set, Wozniacki pressed home the advantage and broke in the first game of the third.
Schiavone made a brave stand in the fourth game as the duo treated the crowd to the rally of the tournament but the Dane was in full flow and wrapped up victory on her fourth match point.
Earlier, Dementieva delivered a far more assured performance against Stosur than she did in her opening 6-1 6-1 defeat by Wozniacki.
Stosur scored an early break in the first set but let the advantage slip when her opponent battled back to 4-4. The Australian survived a scare on serve but held and then broke Dementieva to win the first set.
The Russian upped her game in the second set and for the first time in the tournament Stosur looked rattled, gazing to the heavens in search of answers.
The third set went on serve until the tiebreak when Dementieva's consistency made the difference.
