Summer McIntosh broke the world record in the 200m butterfly on Sunday at the Canadian Swim Championships in Montreal, shattering the oldest world mark in women's swimming.
McIntosh, a three-time champion at the 2024 Paris Olympics, won the Canadian 200 fly title in 2mins 1.65secs to erase the prior world record of 2:01.81 set by China's Liu Zige in October of 2009 at Jinan, China.
The world record had been the last in women's swimming from the supersuit era, when record books were rewritten by swimmers in polyurethane suits before they were banned in 2010 by world governing body FINA.
"As you can see by emotions, this means the absolute world," McIntosh told event broadcasters after the historic victory. "Growing up, this is the one world record that I thought I would never break.
"To do it tonight is really special in front of a home crowd. It means the absolute world. I'm in shock right now."
The 19-year-old from Toronto swam the first 50m in 27.45 seconds then charged at the finish as the crowd roared.
"The last 50 was pure adrenaline," McIntosh said. "I could hear the crowd going crazy and I knew I was probably under, or close to, world record pace, so that's really what kept me going."
McIntosh, whose mother swam in the 1984 Los Angeles Olympics, owns world records in four events, adding her trademark 200 fly to the 200m and 400m individual medleys and the 400m freestyle.
She won the 200 and 400 individual medley Olympic golds in addition to the 200 fly title in Paris.
Her eight career world titles include crowns last year at Singapore in the 200 and 400 IM, 400 free and 200 fly.
McIntosh will be a favourite in multiple events in next month's Pan Pacific Championships in Irvine, California.