ISTANBUL: Maria Sharapova set up a blockbuster WTA Championships final against Serena Williams on Saturday with a crushing 6-4, 6-2 win over world number one Victoria Azarenka.

Olympic, Wimbledon and US Open champion Williams had earlier eased into Sunday’s title match with a 6-2, 6-1 success against an exhausted Agnieszka Radwanska in a repeat of this summer’s All England Club final.

“I have lost to Victoria a few times so I was happy to get the chance to play against her,” said Sharapova.

“Against the world number one, you have to run down every ball. She’s number one for a reason so I had to be ready for every shot.

“It will be a difficult match against Serena. She’s been on fire, she’s the one to beat.”

Not many people expected Sharapova to complete a career Grand Slam by winning the French Open on her least favored clay court surface in June.

And after losing four times out of five to Azarenka this year, a semifinal win indoors in Istanbul did not seem likely either.

But the Russian designed sensibly bold tactics to frustrate the heavy-hitting Belarusian, stuck to them bravely, and executed them excellently.

While Radwanska had had a record-breaking three-and-a-half hour match against Sara Errani the night before, Williams had had a rest day and the statistics showed that the underdog had already run three times as far as the former champion to get to the semi-finals.

Not surprisingly Radwanska had admitted that it would be an achievement “just to get to the court in one piece.”

Serena’s side-to-side ground strokes soon made it clear that she would have to cover large areas of court again and that was something which could not be repeated for long.

“I really wanted to run, but my legs didn’t,” Radwanska admitted.

Williams was certainly sympathetic to the Pole’s predicament.

“I just told her it was awesome that she played so well and played through another match after playing a good eight hours. It was really inspiring for me.”

Despite the mundane encounter, Williams was almost as thrilled as Sharapova.

Waving ecstatically and fluffing up her already voluminous hair she announced that all she wanted to do now was finish 2012 with a win.

That would have special meaning for her, since this has been a year in which she proved she has finally recovered from a horrific 12 months during which a blood clot in her lungs threatened her life.