The first of three new Olympic swimming events got underway Monday with preliminary heats in the women's 1500m freestyle.
There was never a doubt who would set the initial mark.
Katie Ledecky, racing her third event of the day after the 400 free final and the 200 free prelims, claimed the inaugural Olympic record in her strongest event in a time of 15:35.35. The next fastest swimmer, China's Wang Jianjiahe, arrived over six seconds behind.
Ledecky's American teammate, Erica Sullivan, qualified third in 15:46.67, a personal best by nearly five seconds.
The women's 1500 has been a fixture of world championship competition since 2001, though until Tokyo it was a glaring omission – along with the men's 800m – from the Olympic program.
For Ledecky, the world record holder and prohibitive gold medal favorite, the addition comes with a catch. In a testament to her versatility across distances, Ledecky will compete in both the 200 free final and the 1500 free final in the same night Tuesday.