Ian Thorpe congratulates Alexander Popov after the 31-year-old Russian won the 100m freestyle title in Barcelona on Thursday. (AFP)

Barcelona: Michael Phelps smashed two world records in less than an hour to make it four this week and swung away with his second title at the world swimming championships on Friday.

The 18-year-old American, who had broken the 200 metres butterfly and 200 individual medley world marks in semi-finals earlier this week, came out with appetite undiminished and obliterated the 100 butterfly and his own 200 medley mark.

The 100 butterfly world record had stood for just a couple of minutes, with Andriy Serdinov of the Ukraine clocking 51.76 seconds in the first semi-final only for Phelps to annihilate that time when he hurtled through the second semi-final in 51.47. The previous mark of 51.81 belonging to Australia’s Michael Klim had stood since December 1999.

Barely 50 minutes had elapsed before Phelps was back for the 200 individual medley final and destroying the 1:57.52 mark he had set the day before. He was way inside that record schedule all the way and beat it by more than a second in 1:56.04.

Ian Thorpe came through for the silver in 1:59.66, thus equalling the biggest aggregate medal haul in world championship history, having joined Germany’s Michael Gross on 13.

The Australian has 11 gold, one silver and one bronze, comprising two gold in 1998, a record six gold in 2001 and three gold, a silver and a bronze in the Palau Sant Jordi pool this week.

Olympic and defending world champion Massimiliano Rossolino of Italy took the bronze in 1:59.71.

American Amanda Beard equalled the women’s 200 metres breaststroke world record, coming through on the final length of the final to overhaul Australia’s Leisel Jones, who had taken the field out at a breakneck pace.

Beard, double Olympic silver medallist in 1996, swept past her on the last length to touch in 2:22.99 to equal the world mark set by China’s Qi Hui in Huangzhou in April 2001.

Jones took the 200 silver in 2:24.33, while Qi, silver medallist at the 2001 worlds, took the bronze in 2:25.78.

Olympic 1500 freestyle champion Grant Hackett, leading from start to finish, won the men’s 800 freestyle title in the absence of 2001 champion Thorpe, who preferred to try the 200 individual medley.

The 23-year-old Australian, silver medallist last time, won in 7:43.82 from Larsen Jensen of the US (7:48.09) and the Ukraine’s Igor Chervinskiy (7:53.15).

Hanna-Maria Seppala became the first Finnish woman to win a world title when she won the 100 freestyle from Australia’s Jodie Henry and American Jenny Thompson, who collected her 12th world championship medal with a bronze. (Reuters)