It wasn't even close.
Katie Ledecky blasted past her own world record in the 800-meter freestyle, leaving the rest of the field far in her wake as she's done so often in the Rio Olympics, winning her fourth gold medal of these Games.
In defending her gold medal from the London Games, Ledecky became the first swimmer to match Debbie Meyer's sweep of the 200, 400 and 800 freestyles in the 1968 Mexico Games, 48 years ago.
Ledecky's won by nearly a half a pool length, showing her utter dominance at the event. Her 8:04.79 time was almost 12 seconds faster than silver medalist Jazz Carlin of Great Britain. Boglarka Kapas of Hungary took bronze.
"I felt good the whole way through," Ledecky said after the race, adding she knew she was in good shape from the start.
Her qualifying time of 8 minutes, 12.86 seconds was itself an Olympic record, and the 19-year-old American was nearly seven seconds faster than anyone else in that race.
She set the world record four other times in less than three years. It was 8:14.10 before she arrived on the scene.
"I try not to think too much about the history of anything," Ledecky said Thursday. She didn't get to bed until after 3 a.m. that morning after anchoring the U.S. women to victory in the 4x200 free relay on Wednesday. "It's all just about doing my best every time."
Meyer, who accomplished the feat when she was 16, told USA Today, "[Ledecky] reminds me so much of me 48 years ago… I love watching her swim, absolutely love it. I love seeing that drive. I love seeing the way she attacks things. The way she swims is very much the way I tried to swim."
The gold on Friday brings Ledecky's haul in Rio to four, and she has a silver medal to boot. Only four other female swimmers have ever won four golds in a single games, most recently America's Missy Franklin in London.