MELBOURNE: Canada’s Maggie MacNeil destroyed the 100m butterfly world record Sunday and the United States shattered the women’s 4x100m medley relay mark to wrap up the six-day World Short Course Championships. A third record tumbled in the final race at Melbourne with Australia and the United States finishing in a dead heat to jointly set a new best time in the men’s 4x100m medley. Australia’s Kaylee Mckeown also wrote a slice of history by winning the 200m backstroke to become the first female ever to hold the short course, long course, Olympic and Commonwealth titles in the same event simultaneously. Defending champion MacNeil was behind Torri Huske as they turned for the final 25m lap, but powered home in 54.05 seconds to demolish the previous mark of American Kelsi Dahlia by over half a second. The USA’s Huske took silver ahead of Sweden’s Louise Hansson. It was MacNeil’s second world record of the meet after breaking her own 50m backstroke best on Friday. “I definitely can’t believe it … I am really, really pleased about the result,” she said. “I knew that Torri and Louise would be out fast and my goal was to stick with them and use my back half. South African veteran Chad Le Clos made it a butterfly double by taking out the men’s 100m race in 48.59 to go with his 200m crown. It was his fifth world title over 100m after success in 2012-14-16-18. Backstroke queen Mckeown led from the start to clock 1:59.26, shy of her own world record but ahead of American Claire Curzan and Canada’s Kylie Masse. In the men’s race, Ryan Murphy also led all the way to take it out in 1:47.41 and cement his status as a great after also claiming the 50m and 100m titles. Lithuania’s Ruta Meilutyte, who broke the world record in the semi-finals, was too strong in the women’s 50m breaststroke, coming home in 28.50 with South Africa’s Lara van Niekerk earning silver and American Lilly King bronze. “I have gained so much from this experience,” said Meilutyte. “Although there are horrible things happening in this world it has been a good year for me personally and I am very grateful.” Among the men, Nic Fink edged Italy’s Nicolo Martinenghi in 25.38, adding to the American’s 100m breaststroke title. But Britain’s Adam Peaty only managed sixth.