MONTREAL, July 24 (Reuters) - South Africa's Roland Schoeman set a world record in the semi-finals of the men's 50 metres butterfly at the world championships on Sunday to confirm his place as favourite for Monday's final.

Schoeman, part of the South African team that won the 4x100m freestyle gold medal at last year's Athens Olympics, stopped the clock at 23.01 seconds in the first semi-final, wiping 0.29 off the previous record established by American Ian Crocker in Austin last year.

Crocker won the second semi-final in 23.32 to finish second overall with Ukraine's Sergiy Breus third in 23.53.

Australia's defending champion Matt Welsh missed the semi-finals after finishing 23rd.

His compatriot, Jessicah Schipper, twice broke the championship record in the women's 100m butterfly.

She swam 57.91 in her morning heat to eclipse Jenny Thompson's previous record set at Barcelona two years ago, then went 57.75 in the semi-finals.

"That was pretty good and I'm happy with that but there's still a few things I can improve on," Schipper said.

Her team mate Libby Lenton set the second fastest time, 58.11, despite having to swim the anchor leg in the Australian team that won the 4x100m freestyle gold less than a hour later.

Poland's Otylia Jedrzecjak, the Olympic silver medallist in 100m butterfly and champion over 200m, was third quickest in 58.19.

Japanese world and Olympic champion Kosuke Kitajima broke his own championship record in the heats of the men's 100m breaststroke with the second fastest time in history.

But he had to settle for second fastest overall behind American world record holder Brendan Hansen whose 59.75 was just 0.03 ahead of Kitajima, leaving both men brimming with confidence.

"I held off a little bit and I've still got a lot left in me," Hansen said.

Kitajima replied: "I'm very satisfied with my race and I will do my best tomorrow. I'm confident I will win the gold medal."

American teenager Katie Hoff underlined her status as one of the rising names of women's swimming by leading the qualifiers in the women's 200m individual medley with a semi-final time of 2:11.71.

She was nearly two seconds clear of Zimbabwean Kirst Coventry, the Olympic 200m backstroke champion, with Australia's Lara Carroll third.

"I felt really good and I'm excited about tomorrow night," Hoff said. "My strokes are feeling great."