Winning Michael Phelps lays down gauntlet

The American swimmer, who won eight gold medals at the 2008 Beijing Games, claimed the 100m butterfly title in 50.71 seconds. He is bound to get better for London 2012.

Michael Phelps won an unprecedented eight gold medals at the Beijing Olympics in 2008.

SHANGHAI // Michael Phelps won his third successive 100-metre butterfly title at the world swimming championships Saturday before warning his rivals he could only get quicker ahead of next year's London Olympics.

The 26-year-old American, who won an unprecedented eight gold medals at the 2008 Beijing Games, claimed the 100m butterfly title in 50.71 seconds.

Poland's Konrad Czerniak (51.15) and Tyler McGill (51.26) of the US took the silver and bronze, respectively.

The victory ensured Phelps, who was also first in the 200m butterfly on Wednesday, recorded a butterfly double for the third consecutive world championships.

"I thought I could be a little faster," he said after the 100m. "Looking at the finish and the scoreboard, I think I was a little long, my turn was a little long.

"Those are the two things that can potentially make me faster."

Phelps used his finishing speed to post the fastest qualifying time after he found himself in fifth place at the turn.

He was better positioned on Saturday, turning for home in third before another late burst propelled him clear of the field.

It was Phelps's third gold of the championships, having also swum the lead-off leg for the US in the 4x200m freestyle relay on Friday.

In addition, he won two 200 silvers in the individual medley and the freestyle - both behind compatriot Ryan Lochte - and a bronze in the 4x100m freestyle relay.

Phelps, who lacked motivation to train after his exploits in Beijing, said his performances in Shanghai would give him an indication of where he stood heading into the Olympics - his final Games before retirement.

"It's been an OK week, some surprises," he said. "Throughout the week I was not in the best physical shape. This is going to be a lot of help that I can work on next year."