American Michael Phelps smashed Ian Thorpe's 200 metres freestyle world record on an extraordinary evening at the world championships on Tuesday.

Four world records tumbled in the space of 90 minutes at the Susie O'Neill pool with Aaron Peirsol, Natalie Coughlin and Federica Pellegrini setting new marks in one of the most remarkable days in the event's history.

 Peirsol and Coughlin, both from California, shattered their own 100 backstroke records to win gold and Italian Pellegrini claimed the women's 200 freestyle record in the semi-finals.

Kate Ziegler of the US and Australia's Leisel Jones also broke championship records with the second fastest times in history to win their events, but it was Phelps who stole the show.

The 21-year-old left his rivals in his wash as he raced to a stunning victory in one minute 43.86 seconds, wiping 0.20 seconds off the previously untouchable record of 1:44.06 set by Australian Thorpe at the 2001 world championships in Japan.

Pieter van den Hoogenband of the Netherlands, who was second behind Thorpe in Fukuoka, had to settle for the silver medal again while South Korea's Park Tae-hwan was third to add a bronze medal to the gold he won in the 400 freestyle on Sunday.

Thorpe beat Phelps and Van den Hoogenband at the 2004 Athens Olympics in swimming's so-called "race of the century" but the trio never raced again because Thorpe missed the last world championships in Montreal before announcing his retirement in November.

"I did want to race (Thorpe) here, I'm a little disappointed at that," Phelps said. "But I was able to get there and race one of the best in Pieter."

ON COURSE

Phelps also won gold in the 4x100 freestyle relay and remains on course to eclipse Thorpe's record of six gold medals at a single world championships.

Coughlin won the women's 100 backstroke final in 59.44 to shave 0.14 seconds off the previous record of 59.58 she set at Fort Lauderdale, Florida in 2002.

She was pushed all the way by Laure Manaudou of France, who became only the second woman to break a minute for the event. Japan's Reiko Nakamura came third.

"It has been a goal of mine for five years now to break my best, which is a world record," Coughlin said.

"I felt really strong and confident. I knew exactly how I needed to swim that race to break the record and I did."

Peirsol provided the US with their third world record of the night by storming to victory in 52.98 to slice 0.19 off the previous record of 53.17 he set at Indianapolis in 2005.

Ryan Lochte of the U.S. finished second and Britain's Liam Tancock was third.

"I think it's the most impressive team I've ever been on. Michael was incredible, Natalie did well, so I had to do something too," said Peirsol, who has won the 100 and 200 world titles three times each.

Pellegrini pulled off the biggest surprise of the night when she broke Franziska van Almsick's five-year-old record for the 200 freestyle, stopping the clock at 1:56.47 to eclipse the German's mark of 1:56.64.

Jones won the women's 100 breaststroke final in 1:05.72, 0.63 outside the world record she set in Melbourne at last year's Commonwealth Games.

The 21-year-old from Brisbane posted the second fastest time in history to defend the world title she won in Montreal two years ago and finish ahead of American Tara Kirk and Ukraine's Anna Khlistunova.

The US won a fourth gold medal on Tuesday when Ziegler came within a second of breaking the oldest world record in swimming, the women's 1500 freestyle.

Ziegler led all the way to win the longest event on the programme in 15:53.05 seconds, just 0.95 outside the world record of 15:52.10 set by Janet Evans in 1988.

Switzerland's Flavia Rigamonti finished strongly to grab the silver medal with Japan's Olympic 800 freestyle champion Ai Shibata third.