In the opening act for what promises to be a thrilling showdown on the first day of swimming at the Paris Olympics, 2016 gold medalist and former world-record holder Katie Ledecky set the top mark of the women’s 400m freestyle preliminary heats Saturday morning in Paris.

FULL RESULTS

Ledecky finished in 4:02.19 after chasing down and overtaking Australia’s Ariarne Titmus – the Tokyo gold medalist and current world record holder – in the last 100m of the third and final heat.

Heat 2 featured the third former world-record holder, Canada’s Summer McIntosh. However, McIntosh finished one tenth behind New Zealand’s Erika Fairweather, the 2024 world champion (in the absence of Ledecky, Titmus and McIntosh). 

The four swimmers were separated by just 0.46, setting the stage for what many have anticipated as a “race of the century” caliber final scheduled for 2:52 p.m. ET.

The pace will be upped significantly in that final, with all four swimmers boasting personal bests well south of four minutes.

Titmus’ world record currently stands at 3:55.38, set at the 2023 world championships, the last major meet to feature the Aussie, Ledecky and McIntosh. It will likely take a new all-time mark to win gold in Saturday’s final.

Coverage of Saturday's finals session begins at 2:30 p.m. ET on NBC, Peacock, NBCOlympics.com and more.