Last week at the China Open Flavia Pennetta defeated singles and doubles No.1s on the same day – Caroline Wozniacki and Liezel Huber – thus joining the legendary Steffi Graf as the only other player in history to achieve the feat.

In the Friday's Beijing singles quarterfinals, Pennetta upset top-ranked Wozniacki, and then, together with Gisela Dulko, beat the doubles team of Liezel Huber and Lisa Raymond in the semifinals.

Graf defeated the No.1-ranked player in singles and doubles by winning over Martina Navratilova in Berlin, in 1986, when Navratilova was on top of both the singles and doubles rankings.

Moreover, only five players in history managed to beat both the No.1s at the same tournament: Steffi Graf in 1986, Jana Novotna in 1996, Lindsay Davenport in 2008, Venus Williams in 2009, and now Flavia Pennetta. (source: WTA Tour, photo: sr_cranks)

Retired former world No.1s Kim Clijsters and Steffi Graf played exhibition matches together with ATP stars Andre Agassi and Tim Henman to officially celebrate the new retractable roof over Wimbledon's Centre Court. The event was called A Centre Court Celebration and the new roof was today used for the first time.

Clijsters, who retired in May 2007 but is expected to return to the sport competitively in August, beat Graf in singles 6-4. Graf is not contemplating a comeback, but she said she loved being back on Centre Court ten years after her last visit.

In doubles, Tim Henman and Kim Clijsters defeated the husband and wife duo 7-6. In men’s singles, Agassi beat Henman 6-4.

Additional info: The much-needed roof takes between eight and nine minutes to close. (source: Wimbledon)

The crowd of 15,000 will have an opportunity to watch the men’s singles, ladies singles and mixed doubles exhibition matches on May 17. Tickets will cost £35.00 and will go on general sale March 12.

The construction of the multi-million pound roof, aimed at preventing annoying rain delays, began in 2006. The roof is translucent, so as to allow natural light in, and takes 10 minutes to shut.

As part of the redevelopment, the capacity of Centre Court was expanded from 13,800. (source: BBC, photo: ucayman)

Both the players enjoyed the memories this exhibition brought back, and it could be said that the last time they played each other was also in Tokyo, at the Toray Pan Pacific Open in 1994. Then, Graf was the winner, just as today, with a 6-2 6-4 victory over Navratilova.

In their fruitful careers Graf and Navratilova met 18 times and each won 9 times.

BTW: For those of you who happened to miss the news, Navratilova is Czech again.

You can see more nice pictures from the Tokyo exhibition here. (source: Sportsnet)