Coughlin breaks own 100m backstroke record

American Natalie Coughlin surprised herself by breaking her own 100 metres backstroke world record on Sunday, clocking 59.21 seconds in the preliminaries of the Missouri Grand Prix.

Coughlin, the reigning Olympic champion, took more than two tenths of a second off the previous mark of 59.44 seconds set at the world championships in Melbourne last year.

"If you could see my face, I was slightly shocked," Coughlin told reporters. "It was a strange race. I really didn't expect it."

Coughlin was more than four tenths of a second behind world record pace at the halfway stage but used a strong second leg to set the second world record of the meet.

Zimbabwe's Kristy Coventry shattered the 200 backstroke record on Saturday. Coventry was second to Coughlin in the 100 backstroke preliminaries, clocking 59.61 seconds.

Coughlin's world record was the third last weekend globally after Australia's Eamon Sullivan broke Alexander Popov's eight-year-old mark for 50 freestyle in Sydney to inherit the title as the fastest swimmer in history.