Vancouver’s Annamay Pierse has set the 24th world record at the world swimming championships, eclipsing American Rebecca Soni’s time in the semifinals of the 200-metre breaststroke. Pierse finished in two minutes 20.12 seconds Thursday to edge Soni, who touched in 2:20.22. The two swimmers will go head-to-head in the final on Friday. Earlier in the day, Pierse set a meet record in the preliminaries. Meanwhile, Brent Hayden was unable to defend his title in the 100-metre freestyle. He finished fourth in a time of 47.27 seconds — missing the podium by two one-hundredths of a second. Brazil’s Cesar Cielo Filho took gold in 46.91 seconds and was followed by Frenchmen Alain Bernard (47.12) and Frederick Bousquet (47.25). Also Thursday, Audrey Lacroix of Pont-Rouge, Que., finished seventh in the 200-metre butterfly while Canada’s women’s 4x200 freestyle relay team smashed a national record to advance to the final. The 4x200 team of Genevieve Saumur of Montreal, Julia Wilkinson of Toronto, Alexandra Gabor of Whitehorse and Heather MacLean of Toronto — was fourth in the preliminaries with a time of 7:50.29. The previous Canadian record of 7:56.26 was set at the 2008 Beijing Olympics.