LONDON, England (BBC) – Olympian Aaron Peirsol has become the first swimmer to break the 52-second barrier at 100-metre backstroke.

The 25-year-old reclaimed his world record at the US Championships in Indianapolis in a time of 51.94.

The women’s 50-metre breaststroke record has also been smashed as 15-year-old Amanda Reason clocked 30.23 at Canadian trials for the World Swimming Championships.

After her triumph in Montreal, Reason said: “I kept pushing it through to the end and I did it. This is amazing.”

Canadian teenager Reason eclipsed the previous mark of 30.31 set by Australia’s Jade Edmistone in 2006.

The new world record is the first by a Canadian in a long course pool since Allison Higson broke the 200-metre breaststroke mark in 1988.

“My coach said I had to go out fast and get my head into the motion,” said Reason, a bronze 50-metre breaststroke medallist in the World Junior Championships.

American swimmer Peirsol, who also broke records as a 15-year-old, reclaimed his world record with a remarkable come back over Matt Grevers.

The Olympic champion trailed his rival at 50-metre but powered back to win with Grevers finishing second in 53.11.

“That’s a beautiful race,” Peirsol said. “I knew I could do something special.”

Peirsol’s previous mark of 52.54 which was set at the Beijing Olympics in 2008 was broken by Spain’s Aschwin Wildeboer Faber on July 1.

It was the sixth time Peirsol has lowered the world record in the 100-metre back, an event he has dominated for most of the decade.

“The consistency is the thing I’ve always held myself high on,” he said.

Peirsol took back the world record wearing an ArenaX-Glide that covered his legs, one of the newer suits approved by governing body FINA.

“I feel like if I would have worn another suit, I probably would have broken the world record anyway tonight by the way I was feeling,” he said. “That’s one race that’s coming a little easier for me and tonight I just felt really good.”