ROME: On a night when five more world records fell, Aaron Peirsol still figured he could just coast through the semi-finals of his signature event.

Peirsol didn’t want to push himself too hard, figured he could save a little energy for the final swim.

But the world-record holder and two-time Olympic champion in the 100-meter backstroke was stunningly knocked out in the semi-finals on Monday, caught off guard by the lightning-quick times that dealt another beating to the record book on the second day of the World Swimming Championships.

There’s been a staggering 11 world records set at the final major meet for high-tech bodysuits, with six more days still to go. Peirsol was wearing one of those suits, but it sure didn’t help. His time of 53.22 seconds was nearly a full second behind the top qualifier, Japan’s Junya Koga, and a tenth of a second out of the eighth spot, the last that advances to the final.

Michael Phelps was taking no chances. In his first individual event, Phelps breezed through the preliminaries and semi-finals of the 200 freestyle.

Germany’s Paul Biedermann already showed no respect for the swimming greats when he knocked off Ian Thorpe’s iconic record in the 400 freestyle, after breezing through the semis in 1 minute, 43.65 seconds —not far off Phelps’ world record of 1:42.96. Phelps won his semis heat and was third-fastest overall at 1:45.23. The record-breaking carried on at a staggering pace on Monday. Brenton Rickard of Australia set a world standard in the very first event, winning the 100 breaststroke in 58.58 to take down Kosuke Kitajima’s mark of 58.91.

Sweden’s Sarah Sjostrom broke the record she set a day earlier in the semi-finals of the 100 butterfly at 56.06, shaving nearly four-tenths off the 24-hour-old record.

Ariana Kukors provided a rare bright spot for the struggling American team in the 200 individual medley, beating Olympic champion Stephanie Rice of Australia in 2:06.15.

Rebecca Soni of the US and Russia’s Anastasia Zueva both set world records in the semis. Soni’s time of 1:04.84 in the 100 breaststroke beat Leisel Jones’ three-year-old record of 1:05.09, while Zueva won her heat of the 100 back in 58.48, wiping Kirsty Coventry’s mark of 58.77 off the books.