The 2004 champion Maria Sharapova came from a set down to defeat world No.2 Svetlana Kuznetsova 5-7 6-2 6-2 at the Sony Ericsson Championships in Madrid.

The first set was tight, both the players made one break, but towards the end of the set, when Sharapova served to take the match to a tiebreak, she made two errors, and before you knew it, Kuznetsova won the set on her first set point.

The other two sets were a different story. In the second set Sharapova broke her opponent twice; the first time frustrated Kuznetsova slipped two times in a row and failed to return the ball, while the second time she double-faulted and gave Sharapova the huge lead. In the deciding set, Sharapova was definitely the dominant player. Again she broke Kuznetsova two times, and again Kuznetsova was devastated. The first time Sharapova broke her compatriot without losing a point, while the second time Kuznetsova was leading 40-0 but lost her serve very quickly!

Having lost this match, Svetlana Kuznetsova failed to qualify for one of the semi-final berths at the Sony Ericsson Championships. This means that both Maria Sharapova and first-time qualifier Ana Ivanovic join Justine Henin in the semis. (photo via Getty Images)

I’ve just heard on CNN that Serena Williams pulled out of the Sony Ericsson Championships in Madrid.

Unbelievable, both the Williams sisters had qualified for the season-ending event, but had to withdraw. Venus said some time before the tournament that she wouldn’t compete because of dizziness she had suffered during the US Open.

World No.5 Serena Williams retired from her match against Russian Anna Chakvetadze on Wednesday, due to left knee injury, but was hoping to continue her fight for the Sony Ericsson Championships title. What a disappointment!

The American will be replaced by France’s Marion Bartoli. (photo via Getty Images)

Serena Williams retired with a left knee injury while trailing 6-4 to Anna Chakvetadze at the Sony Ericsson Championships. The 26-year-old American, who won the event in 2001, hopes that she will be able to continue to compete in Madrid.

"Before the match I had taping for prevention since I was feeling a little tight in both knees. I thought I was tighter in the right knee but then, once I had to increase my range of movement, the left knee got worse," said world No.5 Williams.

"I've had issues with my knees before especially the left knee since that's the one I had surgery on in 2003. It's unfortunate it's happened now and I can't stress how disappointed I am.

"Right now it's swollen and I'm going off to have an MRI at the hospital to see exactly what the problem is. It is my intention to play on in this event."

I’m still waiting for the news whether Serena will continue to play in Madrid. If not, France’s Marion Bartoli will step in. (source: Reuters, photo via Getty Images)

The season-ending Championships order of play for Thursday, November 8, 2007:

From 18.00hrs (Madrid time)

1. Svetlana Kuznetsova vs. Maria Sharapova
2. Justine Henin vs. Serena Williams (not before 20.00hrs)
3. Jelena Jankovic vs. Anna Chakvetadze

Serena Williams was forced to retire from her first match at the 2007 Sony Ericsson Championships because of a left knee injury. Having lost the opening set 4-6, Williams shook hands with Chakvetadze, and left the court in tears.

The Russian was sad that she won the match in this way, but the triumph is very important to her since it keeps her in competition for the semifinals (Chakvetadze lost her first match at the WTA Championships to defending champion Justine Henin).

I still don't know if Serena will be able to quickly recover from the injury and continue to compete at the season-ending Championships, but if not, Marion Bartoli will take her place as she is the first alternate. (photo via Getty Images)