DOHA: Russia’s Dinara Safina hobbled out of the WTA Championships here on Wednesday, surrendering the year-end world number one ranking to Serena Williams in the process.Williams then celebrated the landmark by beating sister Venus 5-7, 6-4, 7-6 (7/4), sending the defending champion to a second defeat and virtually certain of exiting the US$4.55 million tournament.

The 23-year-old Safina quit her opening match against Jelena Jankovic with a lower back injury with the score at 1-1 in the first set and after only 13 minutes on court.

“My body just gave up, and I couldn’t handle the pain anymore,” said Safina, who had gone back to the top of the rankings on Monday, but only with a 155-point lead on Williams.

The American won her opener on Tuesday against Svetlana Kuznetsova, and then added more ranking points by defeating Venus.

“It’s a great feeling to be world number one, but I feel really sorry for Dinara. She’s a great player and never gives up,” said Serena, who was also the year-end number one in 2002.

“It’s a shame for the tournament that she couldn’t get through to the final.”

Organisers said that fellow Russian Vera Zvonareva, the 2008 runner-up, would take Safina’s place in the competition.

Safina said she had started feeling the inflammation in her lower back on her way to her third title of 2009 in Portoroz in July, but had been determined to keep playing to stay on course for the year-end top spot.

“I was advised to take a break after the US Open. But I thought that I was chasing this No. 1 place, I was fighting with my body.

“Maybe I should have stopped after the US Open. But for two tournaments – in Beijing and Tokyo – it didn’t bother me that much.”

Safina, whose earlier 25-week reign as world number one ranking had come under fire due to the glaring absence of a major title on her CV, said she was confident that surgery wouldn’t be required.

“It’s the time, then it’s the rehabilitation. I have to work on my muscles, on my core stability. As I’m tall, I need to be strong. This is going to be a very long procedure.”

Safina added that she will also have to make a decision on whether or not to skip the 2010 Australian Open in order to complete her recovery.

Safina’s retirement leaves the White Group in the eight-player WTA Championships evenly-poised with Jankovic, Caroline Wozniacki and Victoria Azarenka all with one win with the top two making the semi-finals.

The Maroon Group has Serena Williams on top with two wins, Elena Dementieva has one win while Kuznetsova and Venus Williams are winless.

Serena’s victory over Venus was her 12th in 22 family meetings, but it came in a gruelling encounter which finished after midnight.

Venus had a match point in the 12th game of a scrappy deciding set which featured six breaks of serve.

But Serena, the champion in 2001, eventually clinched the match with her 12th ace, leaving Venus to rue her 10 double faults.

Defeat left Venus needing an astonishing set of results to give her a place in the next round, and she appeared to have accepted her fate.

“I would have liked to have won but I hope to come back next year and fight for the title,” said the 29-year-old who hasn’t won a title for eight months.

In the day’s other match, Danish teenager Wozniacki, the US Open runner-up and world number four, marked her debut by saving a match point in a 1-6, 6-4, 7-5 win over best friend Azarenka. — AFP