Summer McIntosh came within a whisker of breaking a third world record at the Canadian swimming trials on Tuesday after finishing 0.45 seconds outside Liu Zige's 200m butterfly mark set during the era of the now-banned "super-suits".
Three-time Olympic champion McIntosh, who set world records in the 400 freestyle on Saturday and the 200 individual medley on Monday, clocked 2:02.26 to post the second-fastest women's 200 butterfly in history.
The 18-year-old was on world record pace when she made the final turn but fell just short of Liu's 2:01.81 set in 2009.
"I was kind of upset with myself with the finish," McIntosh said. "My last stroke was just a little bit wonky. I can definitely find the other little deficiencies through the race.
"The fact I'm knocking on the door of that world record is really encouraging. That's the one world record I never thought I would even come close to. To be pretty close to it is pretty wild."
McIntosh's time was also more than 10 seconds under the minimum qualifying mark of 2:13.73 for the world championships in Singapore in July and August.