In one of the most consequential non-Olympic races in years, all-time swimming great Katie Ledecky could face an unprecedented challenge Saturday from Canadian teen Summer McIntosh.

Also Friday, Toronto’s Josh Liendo and Montreal’s Ilya Kharun booked spots in the men’s 100-metre butterfly final Saturday. The two shared the Olympic podium in Paris last year, with Liendo taking silver and Kharun the bronze. Liendo turned in the second-fastest time in the semifinals of 50.24 seconds, while Kharun was fourth in 50.39.

McIntosh also joins the Canadian history books as one of just three swimmers from Canada to achieve double gold at the Olympics and the only female.

Canadian swimming sensation Summer McIntosh won her third gold medal of the World Aquatics Championships in Singapore but fell agonizingly short of breaking the 200-meter butterfly world record.

McIntosh absolutely dominated the field, swimming to a time of 2:01.99. Despite leaving her competitors behind, there was some slight disappointment by the 18-year-old phenom after she touched the wall and realized that she came within 18 hundredths of a second of erasing the oldest record in women's swimming.

Toronto’s Summer McIntosh, seen here in the women’s 200-meter individual medley final at the world aquatics championships in Singapore on Monday, is on a quest for five gold medals here.