Roland Schoeman celebrates winning the 50m butterfly gold with a world record at the World Aquatic Championships in Montreal on Monday. (Reuters)

Montreal: Roland Schoeman broke his second world record in 24 hours to win the 50 m butterfly final Monday and become the first South African to capture a world swimming championship title.

The 25-year-old thrashed his way down the Montreal pool in a slick 22.96 seconds to shave 0.05 off the world record he set in Sunday’s semi-finals and add a world title to his Olympic gold from Athens last year.

Jessica Hardy also set a world record in the semis of the women’s 100m breaststroke Monday while her fellow Americans Brendan Hansen and Katie Hoff swam the second fastest times in history to win gold in their respective finals.

Hansen won the men’s 100m breaststroke after a desperate struggle with his Japanese rival Kosuke Kitajima while 16-year-old Hoff enhanced her reputation as one the rising stars of women’s swimming with a runaway victory in the 200m medley.

Jessicah Schipper won the women’s 100m butterfly final to provide Australia with their third gold medal from the first two days of the championships, level with the US on top of the medals table.

Michael Phelps recovered from his shock failure in the 400m freestyle on the opening day to qualify fastest for Tuesday’s 200m final.

Grant Hackett, who cruised to victory in the 400m after Phelps failed to make the final, was fourth fastest in the 200m semis.

But it was Schoeman, who became South Africa’s most decorated Olympian when he won gold, silver and bronze in Athens, who stole the limelight.

He made a flying start off the blocks and quickly built up a lead which he held right through to the end, leaving former world record holder Ian Crocker of the US in his wake.

Crocker took silver in 23.12 and Sergiy Breus of Ukraine the bronze in 23.38.

Hansen won in a time of 59.37, just 0.07 outside the world record he set at last year’s US Olympic trials at Long Beach, California, to claim his first 100m title after a series of heartbreaking losses to Kitajima.

The 23-year-old finished second to Kitajima at the 2003 world championships in Barcelona then again at Athens last year when he went into the Olympics as the hot favourite.

“This was a second chance for me and I didn’t want to screw it up,” Hansen said. “What makes a great swimmer is someone who can come back from a great disappointment and go even faster.”

Hoff had failed to make it past the heats in Athens after her nerves got the better of her, but she made up for that disappointment with a brilliant performance in the medley final.

Her winning time of 2:10.41 seconds was just 0.69 outside Wu Yanyan’s 1997 world record of 2:09.72, a mark that has been virtually untouchable for the past eight years.

Hoff was actually ahead of the world record pace at each of the three turns but faded on the last lap and had to be content with the second fastest time in history.

Zimbabwe’s Olympic backstroke champion Kirsty Coventry was second in 2:11.13 while Australia’s Lara Carroll was third in 2:13.32.

Schipper won the women’s 100m butterfly final in 57.23 seconds, making her the third fastest woman in history in the event. (Reuters)