Phelps breaks 100m fly world record

Michael Phelps broke the 100m butterfly world record on Thursday night, evidence that his post-Olympic transition is right on track.

Phelps, winner of eight gold medals at the Beijing Games last August, won in 50.22, slicing 18-hundredths of a second off the previous record of 50.40 set by compatriot Ian Crocker at the 2005 World Championships in Montreal.

"It was big," Phelps said of the achievement.

"This is something I really wanted to accomplish."

The performance took Phelps's current tally of individual world records to five, to go with three relay world records.

Since 2001, when he set his first world record in the 200m butterfly, Phelps has set at least one world record in all but one year - 2005.

That was another post-Olympic year, and Phelps's coach, Bob Bowman, said he hadn't been sure that Phelps would lower a world mark this season as he retools his training to tackle shorter events.

"I was hoping he'd be on the World Championship team," Bowman said.

"I wasn't sure he'd break a world record this year."

In fact, Phelps has now qualified for three events at the upcoming World Championships in Rome, after victories in the 200m free and 200m butterfly on Wednesday.

Beijing medallists Dara Torres and Rebecca Soni also booked championship berths, along with Nathan Adrian and Elizabeth Beisel.

Torres, 42 and battling a bum knee that will require surgery later this year to address a torn tendon and arthritis, won the 50m freestyle in 24.43.

It was well off her American record of 24.07, set in her three-silver campaign in Beijing. It will be Torres's first World Championships since 1986.

"It's a great feeling to be able to come out here and still race, but that time won't medal at the world championships," she said.