INDIANAPOLIS: Olympic champion Aaron Peirsol reclaimed the 100m backstroke world record Wednesday with a time of 51.94sec, re-establishing himself as the man to beat at the World Championships this month.

Peirsol, who won Olympic gold in a then-world record of 52.54 at Beijing last year, admitted he was surprised to see the record fall to Aschwin Wildeboer Faber, who turned in a time of 52.38sec in leading off Spain's medley relay at the Mediterranean Games in Pescara, Italy, on July 1.

Wildeboer Faber's performance had ended the American's near five-year reign as world record-holder, but as it turned out, only briefly.

"Actually, when the world record was broken, it was a total surprise," Peirsol said. "My goal going into the meet was to try to break it anyways, and that was a little added motivation, most definitely.

"Yeah, the guy got to hold it for a week. I'm sure he's very happy about that. In two weeks, he'll get his chance again." Peirsol, 25, lowered the 100m backstroke mark for the sixth time in his career.

Matt Grevers was barely ahead of Peirsol at the turn, but settled for second in 53.11.

Peirsol said breaking the 52-second barrier was in his mind going into the race.

"It was in my head, getting that or better," he said, adding that his race was pretty close to perfect.

"That was just a great swim," he said. "I mean, that was just great.

"Anytime you can have a performance like that, you feel like you've really done something where you don't look back and say, well I probably could have done this or this better, it's a bit of a relief. It's great to know what I'm capable of." Peirsol raced in an Arena X-Glide, one of the new generation of polyurethane-based suits, but chose a style that left his torso bare.

"It just wasn't for me," he said of the full bodysuit. "I'm not saying it doesn't work for other people. I wanted to do what I was comfortable with. This was good enough." He said the suits, which have sparked controversy for their possible performance-enhancing properties, make some difference, but he thought his performance would have been within his scope in any case.

"The suits definitely have an impact, I do believe that," he said. "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."