American Brendan Hansen broke his own world record in the men's 100 metre breaststroke at the US swimming championships in Irvine, California on Tuesday.

Hansen, the Olympic silver medallist in Athens, touched in 59.13 seconds to better the time of 59.30 he set at the 2004 US Olympic trials.

With a near capacity crowd at the William Woollett Aquatics Centre cheering him on, Hansen raced home almost a second clear of Olympic team mate Scott Usher, who was clocked in 1:01.11.

"I didn't think I'd come to nationals and break the 100," Hansen said on the US Swimming website. "I thought the 200 was more in sight.

"I just wanted the opportunity. Just give me a lane and give me the chance.

"This whole summer has been special for me so far. It was just a matter of me putting all the little things together and just having a good race."

Hansen also holds the world record in the 200m breaststroke.