Rebecca Soni
 / AP Photo/Michael Sohn
ROME (AP) — American Rebecca Soni has set the ninth world record of the swimming championships by breaking her own mark in the 100-meter breaststroke.
Soni touched with a time of 1 minute, 4.84 seconds in her semifinal heat Monday. That knocked off the record of 1:05.09 held since 2006 by Australia's Leisel Jones.
Six records were set on the opening night of the world championships, the last with high-tech bodysuits. Two more fell in the first two finals Monday, to Brenton Rickard of Australia in the 100 breast and Sarah Sjostrom of Sweden in the 100 butterfly.
The biggest stunner, though, came in the 100 backstroke, where world-record holder and two-time Olympic gold medalist Aaron Peirsol failed to qualify for the final Tuesday.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
ROME (AP) — Aaron Peirsol has failed to qualify for 100-meter backstroke final at the world swimming championships on a day two more records fell in two earlier races.
Peirsol had the ninth-best time in the semifinals. It was a stunning development considering he won the 100 back at the last two Olympics and set a world record in the 100 back this month.
But his semifinal time of 53.22 was nearly a second behind top qualifier Junya Koga of Japan at 52.39. Peirsol was a tenth of a second out of the eighth spot, which would have gotten him through to the final.
Australia's Brenton Rickard and Sarah Sjostrom of Sweden set world records about 5 minutes apart to win the men's 100 breaststroke and the women's 100 butterfly.