Samuel Groth 163 MPH Serve, In a challenger event in South Korea, the fastest record serve in tennis has a new mark, set by the 340th-ranked male in the world. Australia's Sam Groth fired up 263 kph serve in the event, according to a report by Reuters.
The ATP Tour said on Saturday that Groth, ranked 340 in the world, produced the serve in a second-round match against Belarusian Uladzimir Ignatik in Busan.
That's about 163 mph, by the way.
Groth bested the previous fastest recorded serve of 251 kph set by Croatian Ivo Karlovic in the 2011 Davis Cup against Germany. Groth wound up losing the match where he recorded the serve to Uladzimir Ignatik in two sets, 6-4 and 6-3. The ATP doesn't officially recognize speed records because of the variance between radar guns, but did note that the radar guns used were approved equipment.
Source:http://www.sbnation.com/tennis/2012/5/12/3016137/sam-groth-records-fastest-serve-at-263-kph
