Ariarne Titmus rival Summer McIntosh hands US legend Katie Ledecky first home 400m freestyle defeat in 11 years

For the first time in 11 years, Katie Ledecky has lost a 400 metres freestyle race in an American pool.

Canadian teenager Summer McIntosh took the title at the US Open championships in Greensboro, North Carolina, beating 26-year-old Ledecky by nearly three seconds.

McIntosh, who swims for the Sarasota Sharks club in Florida, took the title in a meet record of 3 minutes 59.42 seconds, while Ledecky, a seven-time Olympic champion, touched next in 4:02.38.

Ledecky’s last loss in the 400 free in her home country was at the 2012 US Olympic trials, when she placed third at age 15.

Last March, the 17-year-old McIntosh also snapped Ledecky’s nine-year US win streak in the 200 free.

The significance of McIntosh’s latest victory is difficult to gauge, since swimmers are at different stages of their training cycles as they ramp up preparations for the Paris Olympics in eight months’ time.

McIntosh held the 400 free world record for three months before it was reclaimed by Australia’s Ariarne Titmus with a winning time of 3 minutes 55.38 seconds at this summer’s world championships in Fukuoka, Japan.

Ledecky was runner-up at worlds — swimming in a time of 3 minutes 58.73 seconds — while McIntosh struggled to a fourth-place finish, with New Zealand’s own teenage star Erika Fairweather pipping her Canadian rival to claim bronze.

McIntosh’s comeback victory after the disappointment of Fukuoka helps set up another tantalising battle in Paris between three of the sport’s biggest stars.

Their battle in the 400 metres free at the World Championships was billed as the race of the century, but was ultimately a disappointment for McIntosh.

However, the then-16-year-old McIntosh still had a successful championships, winning the 200 metres butterfly and 400 metres individual medley, and seems set to star in the pool in Paris.

Both Titmus and McIntosh will skip the Doha World Championships, set to take place in February, to focus on the Paris Olympics starting in late July.

Titmus, as well as holding the world record, is also the reigning Olympic champion in the 400 free, with Ledecky taking gold in the event at the 2016 Rio de Janeiro Games.

AP/ABC