Having come close to achieving dreams without sleep, Maria Sharapova was resting yesterday in the knowledge that a perfect end to a fairytale year is within her grasp.

The game’s greatest survivor overcame constant deficits in a three-hour match with Agnieszka Radwanska which finished in the early hours of yesterday, carrying Sharapova exhausted to her bed and to a place in the semi-finals of the WTA Championships, being played in Istanbul.

It means the Russian can still finish a character-defining season in which she completed a career Grand Slam by capturing the season-end title she won in her breakthrough season eight years ago.

For a player who was warned she might never be the same after a shoulder operation four years ago, and who has had to compensate for a reduction in the effectiveness of her service ever since, it is all a massive achievement.

“It was such a physical match,” said Sharapova after a 5-7, 7-5, 7-5 win which equalled the longest in number of games of any match in the 40-year history of the WTA Championships.

“It just came down just to a few points in the end. It was an example of not playing my best tennis at all, fighting through it, hanging in there, and getting it done.

“No matter if it’s, you know, a hard shot or a lower slice that has no pace, she makes you work for it,” Sharapova said of Radwanska whose intelligent, varied game dominated many periods of the match.

“But I found a way to get through those points against her which is not always easy, especially on a slower court like this. I fought and I won, so I’m happy.”

Sharapova can rest in the knowledge that she can afford to lose her last group match, against Samantha Stosur the 2011 WTA champion from the Czech Republic.

Yesterday’s Results

Li bt Kerber 6-4, 6-3; Williams bt Azarenka 6-4; 6-4; Errani bt Stosur 6-3, 2-6, 6-0.