Michael Phelps of the U.S. swims to a win in the men's 200m butterfly final at the USA Swimming National Championships in Indianapolis, Indiana July 8, 2009. [Xinhua/Reuters Photo]

Beijing Olympics eight-title winner Michael Phelps broke the world record in the men's 100-meter butterfly at the U.S. swimming championships on Thursday in Indianapolis.

Phelps collected five individual world records to his name when he swam in 50.22 seconds, beating compatriot Ian Crocker's mark of 50.40 set at the 2005 world championships in Montreal in the U.S. trial for the up-coming world championships.

Phelps led at 50 meters with a split of 23.83, just three-tenths off world-record pace and pulled clear to beat Tyler McGill, who touched in 51.06.  Aaron Peirsol was third in 51.30.

U.S. swimmer Michael Phelps looks to the stands after setting a new world record in the Men's 100m Butterfly at the USA Swimming National Championships in Indianapolis, Indiana, July 9, 2009. [Xinhua/Reuters Photo]

Phelps holds world records in the 100 and 200 flys, 200 and 400 individual medleys, and the 200 free.

Phelps had owned the 100 fly mark for a day at the 2003 worlds in Barcelona. But Crocker took it from him a day later, and then lowered it twice more.

(Xinhua News Agency July 10, 2009)