WTA Championships: Ana Ivanovic gets her cake then pulls out; Serena Williams withdraws too

We don't get to see Fernando Verdasco celebrating Ana Ivanovic's 21st birthday.

Instead WTA boss Larry Scott and tournament director Karim Alami were the guys celebrating Ivanovic's birthday at the VIP Village of the Khalifa International Tennis Complex.

They presented her with a cake, shaped like a tennis racquet, made by Le Notre Paris.

The bad news is Ivanovic announced today that she has withdrawn from the Sony Ericsson Championships due to a virus.

The 20-year-old beauty has felt unwell throughout her stay in Doha and was affected by illness in her opening two round-robin matches.

Good for Agniezka Radwanska though as she will take on Svetlana Kuznetsova in Ivanovic's place.

"It's obviously, very, very hard for me," said Ivanovic.

"After the other night's match, it was a very intense and long match. I actually started to feel worse. Yesterday I didn't feel good, and today even worse."

"I tried to hit yesterday actually. I was on the court for about ten minutes, and as long as I didn't move it was okay. But if I tried to hit a little bit harder or to move to the side, it was impossible to do."

"Even if I were to step on the court [tonight], I wouldn't even be able to go through a few games."

The withdrawal is obviously a disappointing and sad ending to an otherwise glorious season.

But 2008 isn't all bad as Ivanovic won her first ever Grand Slam title and reached No.1 in the world (plus she also pocketed $100,000 at Doha despite the disappointing result).

She said: "Even though I had a tough few months, I still think this was the best year of my career so far. I won a Grand Slam, and I reached the position of No. 1. So there's lots of positive things to take from this year."

In another shocking withdrawal, Serena Williams cited a stomach injury when she pulled out of her match at the Sony Ericsson Championships against Elena Dementieva, who advanced to the semifinals.

“I did feel pain last night,” the U.S. Open champion said.

“I was still in pain just getting out of bed.”

Williams lost to her sister, Venus, 5-7, 6-1, 6-0 on Thursday.

Serena said she might have tweaked a muscle and that doctors had told her to rest.

(Via AP, Ana Ivanovic website, Images via zimbio.com, Yahoo! Sport)