Stephanie Rice sees her new record [GALLO/GETTY]
Australians Stephanie Rice and Emily Seebohn have both broken world record Saturday on the first night of the Australian swimming championships.

Rice rewrote the record books in the 400-metre individual medley, while Seebohm’s effort came in the 50 metre backstroke.

Rice finished in a time of 4 minutes, 31.46 seconds, taking 1.43 seconds off American Katie Hoff's mark of 4:32.89 set on April 1 at last year's world championships in Melbourne.

The eight-day event at the Sydney Olympic Park Aquatic Centre is also serving as Australia's Olympic qualifying meet.

The 19-year-old took almost six seconds off her personal best time.

"I was so in shock," Rice said. "I saw my time ... but I did not think I would go that fast."

Rice was a bronze medalist at last year's world championships in the event.

Laster, Emily Seebohm grabbed the glory in the non-Olympic 50-metre backstroke.

Seebohm finished in a time of 27.95 seconds Saturday, taking 0.05 seconds off American Hayley McGregory's mark set two weeks ago.

"The goal was pretty much all this season to get that world record ... I just had to go under 28 this time," Seebohm said.

Source: Agencies