BEIJING -- Aaron Peirsol of the United States broke the world record to win the men's 100m backstroke gold medal at the Beijing Olympic Games here on Tuesday.

US swimmer Aaron Peirsol competes during the men's 100m backstroke swimming semifinal at the National Aquatics Center in the 2008 Beijing Olympic Games on August 11, 2008. [Agencies]

Peirsol clocked in 52.54 seconds to break his own world record of 52.89 set up in the American trials in July.

His fellow American matt Grevers took the silver in 53.11 and Russian Arkady Vyatchanin finished third in 53.18.