American Breaks World Record

Jenny Thompson rode a "calm, peaceful feeling" to break Mary T. Meagher's 18-year-old 100-meter butterfly record during a record rush at the Pan Pacific swim championships today.

Thompson, 26, was visibly shaken after eclipsing the second-oldest record in swimming, set by Meagher on Aug. 16, 1981.

But before the race, Thompson said she underwent a transformation which helped her.

"I couldn't even believe it," Thompson said. "I didn't feel that great yesterday, this morning or even in the warmup tonight."

"Then, when I was coming out for the race, I felt that calm, peaceful feeling and I knew things were going to be OK."

Australia's Ian Thorpe broke his second world record of the meet, in the 200 freestyle, while South Africa's Penny Heyns got her fifth world record in five races in the 100 breaststroke.

Thompson, a five-time Olympic gold medalist, had a time of 57.88 seconds to lower the mark of 57.93 set by Meagher and break the fourth world record in two days at the championships.

Thompson has never won an individual gold at an Olympics but is favored to take the event in the same pool next year. "The record used to seem like a long shot," said Thompson. "My time's been dropping little by little and it's seemed more like a reality each time. Tonight I didn't know where I was in the race but I just kept going and hoped it was there."

Thompson was followed home by Australia's Susie O'Neill who will attack the oldest record, Meagher's 200 fly mark set three days before the 100 record.

"It was awesome, I feel so good for Jenny," O'Neill said. "She's done it, now I want to do it."

The 16-year-old Thorpe added the 200 record to the 400 he set on Sunday. His time of 1 minute, 46.34 seconds came in a semifinal heat that included previous record holder Grant Hackett, who went 1:46.67 earlier this year.

While Hackett missed the final and said he might pull out of his favored 1,500 event, Thorpe promised he was still not at his peak in the 200.

"I still haven't recovered as much as I'd have liked to from the 400," said Thorpe. "I'm still a bit worse for wear."

Heyns broke her fifth record in five races with victory in the heat. Her time of 1:06.52 broke her own record of 1:06.95 set at the Janet Evans Invitational in Los Angeles on July 19.

At that meet the Olympic champion broke the 100 and 200 records twice each.

"If you know me you'll know that I quite often run hot in the morning, so it wasn't a big surprise," Heyns said. "I never really go for a world record, I just go out for a personal best."

Brooke Bennett, the world championship silver medalist, won the women's 400 freestyle from fellow American Lindsay Benko. Costa Rica's Claudia Poll was third.

Australia's Matthew Dunn won a thrilling 400 medley final against Canada's Curtis Myden, th man who stripped Dunn of the Commonwealth record two weeks ago. Dunn charged back from third at the final turn to get ahead five meters from the finish. American Tom Wilkens, who led with 100 to race, was third.

Australia's Simon Cowley won the men's 100 breastroke in 1:02.06, ahead of compatriot Regan Harrison with Canada's Morgan Knabe third.

Australia led the gold standings with four from eight events with the U.S. on three and Canada at one.

More from CBS News