By Nick Georgandis
TennisNow.com
Serena and Venus Williams, accustomed to life at or near the top, are both set to take unfamiliar steps back next week in the ATP rankings.
Caroline Wozniacki and Vera Zvonareva have the opportunity to vault the American sisters for the No. 1 and 3 spots in the world at the China Open.
Wozniacki pulled within 310 points of Serena by winning the Pan Pacific Open last weekend. She lost in the first round at Beijing last year and needs to reach the quarterfinals to take over the top spot in the world.
Zvonareva is a mere 80 points behind Venus for third. She was a quarterfinalist here a year ago, meaning she'll need to reach the semifinals to overtake the older Williams sister.
The back half of the Top 10 has already experienced a shake-up, with Francesca Schiavone leaping from eighth to sixth for her Tokyo performance. Victoria Azarenka moved from 11th to 10th while Agnieszka Radwanska slipped from ninth to 11th.
Maria Sharapova, the Pan Pacific winner in 2009, fell sharply from 15th down to 21st, a rare spot outside the Top 20 for the former No. 1. Forty-year-old Kimiko Date Krumm, who upset Sharapova the day before her 40th birthday last week, moved up 10 spots from 67th to 57th.
The biggest jump of the week came courtest American Coco Vandeweghe. The 19-year-old surged from 172nd to 113th with her surprise trip to the quarterfinals.
ATP Rankings
There was only one change inside the Top 10 this week in the ATP rankings. Mikhail Youzhny took over No. 8 by winning the Kuala Lumpur tournament, changing places with Fernando Verdasco, who was upset in his first match at the Thailand Open.
The biggest jump inside the Top 50 came from Spain's Guillermo Garcia-Lopez, who upset Rafael Nadal in the semifinals of Thailand, then went on to win the tournament. Garcia-Lopez jumped from 53rd up to 39th, winning his second career title and moving within on spot of his career-best ranking. His ranking gives Spain eight male players inside the Top 50.
The biggest fall inside the Top 50 came from Gilles Simon, who dropped 10 spots to 43rd after not playing Thailand a year after he won the event. Simon, who won Metz a week ago, opted out of the tournament to spend time with his newborn son.