(Reuters) – Venus Williams was denied a chance to better her world record for fastest serve in women's tennis in absence of proper measuring technology at the Pan Pacific Open in Tokyo. Williams blasted a 209km-per-hour serve during Thursday's 6-3 6-7 (4) 6-3 win over Canadian teenager Eugenie Bouchard in the quarter-final match. The WTA uses IDS radar guns to measure service speeds but they are not deployed in Tokyo, the governing body said in an email response to Reuters. It meant that the 33-year-old American's serve of 207.6 km per hour, hit during the 2007 U.S. …