Ledecky, who set a world record in this event at the 2016 Rio Games, came up just short as Titmus wins her first career gold medal.
U.S. swimmer Katie Ledecky has cast a long shadow over her sport since dominating the pool at the 2016 Olympics in Rio. She won four gold medals and one silver, going a perfect 3-for-3 in the three different individual freestyle distances.
After Monday's 400m freestyle final, she will not pull off the same feat in Tokyo.
In one of the most hyped events of these Games, Australia's Ariarne Titmus took down Ledecky to win her first-ever gold medal. Titmus swam the best time of her career—3:56.69—which was a mere 0.23 seconds off of Ledecky's world record from the 2016 Games.
Ledecky's time was 3:57.36, the second-fastest time of her career. China's Li Bingjie came won bronze with a time of 4:01.08.
Titmus, 20, had previously credited Ledecky for serving as an inspiration to her to stay motivated, a sentiment Ledecky shared in a post-race interview.
"We're really friendly. She said she couldn't have done it without me, and I could say the same about her," Ledecky said on the NBC broadcast. "She's really pushed me, and I think it's great for sport."
Titmus's coach, Dean Boxall, was just a tad bit excited at watching Titmus bring home the gold.
Ledecky and Titmus will square off three more times in these Olympics: in the 200m and 800m freestyles, and in the 800m freestyle relay. If those matchups play out in as thrilling fashion as this first leg, we're in for a real treat.
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