Ledecky won her seventh career gold in the event but she was challenged like never before, touching the wall in a championship-record 8min 05.62sec -- a fingertip ahead of Australia's Lani Pallister (8:05.98) and McIntosh (8:07.29).

It was Canadian sensation McIntosh's first defeat of the championships and ended her bid to match Michael Phelps as the only swimmer ever to win five individual golds at a single world championships.

The 18-year-old has already won three golds this week in Singapore.

Ledecky, 28, had too much staying power for her younger rival, with Pallister also in gold-medal contention until the final lunge for the line.

"They pushed me all the way," said Ledecky, a four-time Olympic champion in the event.

"I'm just really happy I could put that together. I just kept telling myself to trust my legs."

The race was billed as a potential changing of the guard, with McIntosh in red-hot form.

She had also threatened Ledecky's world record earlier this year.

Pallister was determined to insert her name into the conversation as well, as the Australian kept pace with Ledecky and McIntosh in a fast start.

The lead changed hands several times but Ledecky, swimming between her two rivals, looked best-placed to strike for home.

In the end it was the American celebrating with her country's flag on the pool deck after an epic race.

"I think I just came into tonight trying to enjoy it as much as I can," said Ledecky.

"I don't feel like I have much to lose at this point in my career.

"I just try to enjoy it every time I get to walk out in front of a crowd like this."

Source: France 24

MN/