The first match lasted three hours, the second 13 minutes and when she pulled up, her back in spasm and unable to move a muscle, Dinara Safina’s quest to finish this year as the world No 1, or start next year with any kind of flourish, was in ruin.

The tears that flowed at the Khalifa complex last night were not for the brother who has one more tournament left as a professional — Marat Safin definitely draws the curtain on his enigmatic career in Paris the week after next — but for a little sister who has endured more questioning of her right to be tagged the best in the world than was really necessary.

Her retirement against Jelena Jankovic after only two games means that Serena Williams, who defeated her sister, Venus, 5-7, 6-4, 7-6 here, will finish the year as the world No 1.

Maybe it was all that time sitting around waiting — they start the round-robin programme in the Sony Ericsson Championships at 5pm, to give the sun the opportunity to lose its potency — that helped to lock the L4 and L5 vertebrae in Safina’s lower back. It took an age for Caroline Wozniacki and Victoria Azarenka to end their duel, with the teenage Dane who reached the US Open final in September, recovering from a break down in the third set to win her opening match in this event, 1-6, 6-4, 7-5.

The crowds had not had enough time to grab a non-alcoholic beverage and whet their whistles before the second affair was halted. Safina moved up the court to play a backhand, stumbled to a halt and knew at once that her season was over. She wept into a towel, could barely raise an arm to the crowd and disappeared.

“I’ve been playing on the pain, on anti-inflammatory, on everything, already for about three months,” Safina said. “It was one of the reasons I had to take a break after the US Open. It was advised. But I thought like, as I was chasing this No 1 ranking, so I was fighting with my body. God knows, maybe I had to stop after US Open.

“But for two tournaments, Beijing and Tokyo, it was quiet, it didn’t bother me that much. So I was still hoping. Then my body just gave up. I did everything possible to play here, but I could not handle any more this pain.”

What is more, Safina has been told to rest for six weeks and says that she may have to skip the Australian Open, which would be a heart-breaker. “At this stage my health is more important,” she said.

So, what was hoped by the princes and the paupers here would be a fight to the finish this week between Safina and Serena Williams — who had said in May: “You all know who the real No 1 is” — was over before Serena took to the court last night.

Remarkably, this will be only the second time in her career — the first was in 2002 — that she has finished a calendar year on top of the women’s pile.