Phelps wins 21st medal as U.S. overtakes China

LONDON, Aug. 3 (Xinhua) -- American swimmer Michael Phelps won the men's 100m butterfly on Friday for his 17th Olympic gold and 21st medal overall, as the United States overtook China on the top of the medals table thanks to a gold rush in the pool.

Phelps clocked 51.21 seconds for the 100m title, adding to his victories earlier in the 200m IM and 4x200m freestyle relay.

Chad le Clos of South Africa and Evgeny Korotyshkin of Russia touched in 51.44 to share the silver medal.

Until Thursday no man had won an Olympic swimming title in three separate Games, Phelps ended that record with his win in the 200-meter medley and Friday's win means he has repeated the same feat in this race.

"I am just happy that the last one was a win. That is all I really wanted and this was by a bigger winning margin than the last two combined," said the 27-year-old Phelps, who has announced to retire after the London Games.

On Sunday, Phelps will take part in his last race - the 4x100m medley relay.

Fellow American Missy Franklin also claimed her third gold medal of the games with a world record-breaking swim in the 200m backstroke. The 17-year-old, who had already won the 100m backstroke and formed part of the U.S. women's 4x100m freestyle relay, touched home in 2:04.06, eclipsing the previous best set by Kirsty Coventry in Rome in 2009.