The 15-year-old Swedish swimmer Sarah Sjostrom broke the world record for the second time in two days to snatch gold in the 100 metres butterfly at an increasingly bizarre world swimming championships in Rome.
New all-polyurethane swimsuits, which are due to banned from January because they are performance enhancing, have prompted a deluge of world records and left swimming's credibility hanging by a thread.
Sjostrom finished 27th at last year's Beijing Olympics but blasted through to be one of 5 world records on the day and the 11th in 2 days of competition.
American Ariana Kukors, who broke the women's 200 individual medley record in yesterday's semi-final, bettered the mark again to take gold in the final edging out Olympic champion Stephanie Rice despite not even qualifying for last year's Beijing Games.
Brenton Rickard of Australia bagged the first world record of the session in the men's 100 breaststroke final.
The world records being set could stand for years to come with governing body FINA poised to confirm a return to all-textile suits and trunks for men in 2010.
Michael Phelps, who won a record eight gold medals at Beijing, acknowledged the improved performance of Paul Biedermann after qualifying third behind the German in the 200 freestyle semi-finals.
Biedermann cracked Ian Thorpe's 400 world record yesterday.
Phelps remarked that Biedermann has gone six seconds faster in the 400 in a year.... the American could struggle for gold in tomorrow's 200 final.
In other world records to fall on the second day of competition, America's Rebecca Soni powered home in the 100 breaststroke semi-finals and Russian Anastasia Zueva made a splash in the semi-finals of the 100 backstroke.
The two biggest surprises on another sweltering Rome day were Olympic champion Aaron Peirsol failing to qualify for the 100 backstroke final and Milorad Cavic grabbing gold in the 50 butterfly final.