TOKYO (AFP) - Venus Williams was denied a new record for the world's fastest serve Friday after tennis chiefs said a bullet delivery clocked at 209 kph was not measured by the right equipment.
The resurgent American star, 33, hit the rocket serve during Thursday's 6-3, 6-7 (4-7), 6-3 quarter-final win over Canadian teenager Eugenie Bouchard at the Pan Pacific Open.
However, the IDS radar guns the Women's Tennis Association uses to track official service speeds are not deployed in Tokyo, meaning Williams's own women's record of 207.6 kph - registered at the 2007 US Open and on her way to winning Wimbledon in 2008 - still stands as the fastest of all time.
The seven-time Grand Slam singles champion, whose ranking has slumped to 63rd in the world after two years of illness and injury problems, admitted she could not believe her eyes when she saw the figure 209 kph flash up on the court-side speedometer.
"I saw that but I was like: 'Is that real?' So I don't know if that's real," Williams said.
"I know I've been serving a lot harder this tournament than since I've come back from my back injury. I couldn't really serve that hard at the US Open (earlier this month) and this summer.
"It feels good but I don't know if it was that hard. I hope it was - that's insane, it's awesome."
The fastest men's serve ever recorded in a professional tournament was a 263kph missile fired by Australian Sam Groth in South Korea last year.