Last year’s runner-up Svetlana Kuznetsova advanced to the semifinals of the China Open, while Elena Dementieva fell at the same tennis complex where she won her Olympic gold medal 14 months ago.

The sixth-seeded Kuznetsova defeated fellow Russian Anastasia Pavlyuchenkova in straight sets, 6-3 6-3, and will next face No.13 seed Nadia Petrova, who followed up her victory over soon-to-be No.1 Serena Williams with a quarterfinal win over Peng Shuai.

The Russian fourth-seeded Dementieva was upset by 12th seed Agnieszka Radwanska 7-5 6-3. The Pole will play 14th seed Marion Bartoli in the semis, who advanced by upsetting seventh seed Vera Zvonareva.

The 2009 China Open champion will collect $775,500. (photo: Jean-Sebastien Marceau)

Has the No.1 jinx already transferred to Serena Williams? Just one round after securing to be ranked No.1 in the next week’s rankings the American lost to Nadia Petrova 6-4 3-6 7-6(5).

The 13th-seeded Petrova and second-seeded Williams each won a set of their third-round match and in the decider they both held serve until tiebreak, having each faced only one break point in that final set. Petrova raced to a 5-0 lead in the tiebreak and although Williams showed resistance the Russian managed to close it out.

Before this encounter, Petrova had defeated Williams only once in their seven previous meetings. (photo courtesy of Women Who Serve)

On Tuesday Maria Sharapova had played a three-hour match against ninth seed Victoria Azarenka and recovered from a 5-2 down in the third set to win the match. That marathon took its toll, and to the delight of the home crowd China's Peng Shuai followed up her upset of defending champion Jelena Jankovic in the second round with a 6-2 6-4 victory over Maria Sharapova in the third.

World No.53 Peng got to lead 6-2 5-2 against Sharapova, and although the Russian almost pulled off one of her trademark comebacks, closing to 6-2 5-4 and getting to deuce, there was no more fuel in her tank and she fell on Peng's third match point.

"My energy level was not where it should have been … there've been occasions where I've been able to fight back, today was just not one of those days unfortunately," said the world No.15 Sharapova, who claimed her first title since returning from injury in Tokyo last weekend.

"She played really solid and really aggressive and did all the right things to win the match." (source: Reuters, photo via Sony Ericsson WTA Tour)

World No.2 Serena Williams is guaranteed to return to the top of the Sony Ericsson WTA Tour rankings, having defeated Ekatarina Makarova in the second round of the China Open.

Serena had one condition to fulfill in order to overtake Dinara Safina – to go further at the China Open than the Russian. It proved to be an easy task as Safina lost in the second round to No.226-ranked Zhang Shuai, who became the lowest-ranked player ever to defeat a world No.1.

Here’s you can watch an interview with Serena Williams after her 6-3 6-2 victory over Makarova.

Safina is spending her 25th week at No.1. Williams will take her place next Monday and begin her 73rd career week as a top-ranked player. (photo: Ralf Reinecke)

Top seed Dinara Safina and third seed Venus Williams lost in the second round of the China Open, with the Russian making history, in a bad way though.

The world No.1 Safina, who is currently spending her 25th week on top of the rankings, lost to No.226-ranked Zhang Shuai 7-5 7-6(5), which is the biggest on-paper upset in Sony Ericsson WTA Tour history. Ouch!

Zhang is now the lowest-ranked player ever to beat a reigning No.1, bettering the No.188 ranking held by Julie Coin as she upset Ana Ivanovic at the 2008 US Open.

The 20-year-old Zhang has won 12 ITF titles, but has never before this week’s China Open won a main draw match on Tour.

"It's very disappointing, I'd like to take a break now. I'm very upset with myself," said Safina, who had an early break in both sets and a set point in the second set.

Last week Safina also lost in the second round of a tournament, falling to 132nd-ranked Chang Kai-Chen at the Toray Pan Pacific Open.

In addition, Safina will lose the No.1 ranking to Serena Williams, if Serena wins her match against Ekaterina Makarova on Tuesday.

The other upset of the day happened when world No.39 Anastasia Pavlyuchenkova scored her second straight win over Venus Williams. The 18-year-old Pavlyuchenkova defeated the seven-time Grand Slam champion last week at the Toray Pan Pacific Open, and today at the China Open the Russian took out the world No.3 American with a score 3-6 6-1 6-4, in the second round as well. (via Sony Ericsson WTA Tour, photo: Jean-Sebastien Marceau)