Summer McIntosh ends Katie Ledecky's 11-year domestic win streak

Canadian Summer McIntosh became the first swimmer to win a 400m freestyle over Katie Ledecky in a U.S. pool in 11 years, taking the title at the Toyota U.S. Open on Thursday.

McIntosh, a 17-year-old who held the 400m free world record for three months last year, clocked 3 minutes, 59.42 seconds in Greensboro, North Carolina.

She distanced Ledecky by 2.96 seconds. It's hard to gauge Olympic prospects on this meet given swimmers are at different points in their training cycles.

Ledecky's last loss in a 400m freestyle in a U.S. pool was when she placed third at the 2012 Olympic Trials at age 15. Last March, McIntosh snapped Ledecky's nine-year domestic win streak in the 200m free. Ledecky is still undefeated in domestic 800m and 1500m free races for 13 years.

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McIntosh is the two-time reigning world champion in the 200m butterfly and 400m individual medley.

She also entered this past July's worlds as the world record holder in the 400m free and finished fourth in a race where Australian Ariarne Titmus regained the world record.

"After that race, I learned a lot about how to get back out after it," McIntosh said on Peacock on Thursday. "I had so many races after that that I was really happy with. No matter how bad one race is, you really get back up and get back into it."

The U.S. Open continues with finals on Friday at 6 p.m. ET, live on Peacock.