ROME, July 29 (Xinhua) -- American Michael Phelps won the men's 200m butterfly gold medal in a world record time of one minute 51.51 seconds at the world swimming championships on Wednesday.

Michael Phelps of the U.S. competes during the Men's 200m Butterfly Final in the 13th FINA World Championships in Rome, Italy, July 29, 2009. Michael Phelps broke his last world record of the event with 1:51.51 to win the gold medal

Phelps bettered the world mark of 1:52.03 he set in winning Olympic gold on August 13, 2008.

    Poland's Pawel Korzeniowski finished second in 1:53.23, beating Japan's Takeshi Matsuda on the final lap.

    Matsuda took the bronze in 1:53.32.