Brazilian swimmer Cesar Cielo Filho celebrates his world mark. ((Gregorio Borgia/Associated Press))

Canada's Brent Hayden failed to defend his title in the men's 100-metre freestyle at the world aquatics championships Thursday in Rome.

The Mission, B.C., native finished fourth in a time of 47.27 seconds, missing the podium by just 2/100ths of a second.

"I was kind of wishing I was going to get something hung around my neck," Hayden said. "But it is a fast world.

Brazil's Cesar Cielo Filho surprised the field by winning the gold medal in a world-record time of 46.91.

French teammates Alain Bernard (47.12) and Frederick Bousquet (47.25) took the silver and bronze, respectively.

"I'm a lot more mature," Cielo said. "It all just came together."

Hayden, the winner at the 2007 worlds along with Italian Filippo Magnini, who finished with the exact same time, kept up with the leaders through the first 50 metres of the race.

He then gave a valiant effort down the stretch, but couldn't catch Bousquet at the wall.

"I put in the effort," Hayden said. "That's all I can ask from myself.

"I did an amazing time. Unfortunately, there were three swimmers faster than me."

'I just give it to them'

Two more men set world records Thursday.

Ryan Lochte of the United States won the gold in the 200 individual medley, clocking 1:54.10 in the year-old Speedo LZR Racer swimming suit. 

Lochte broke the world mark held by compatriot Michael Phelps, who set the standard of 1:54.23 at last summer's Beijing Olympics.

"Everyone is complaining about all these new suits — blah blah blah — and I go out there and wear the same suit that's been out there and I just give it to them," he said.

In the 200 breaststroke, Christian Sprenger of Australia sped to a world record of 2:07.31 in a semifinal heat.

A total of seven world records were shattered on both the men and women's events Thursday, bringing the staggering number to 29 for the meet — four more than at Beijing.

With files from The Canadian Press