RIO DE JANEIRO -- Katie Ledecky delivered another dominating performance at the Rio Games, handily breaking the world record in the 800-meter freestyle Friday.
Ledecky joined Debbie Meyer as the only women to sweep the three longer freestyle events at the same Olympics.
Meyer took the 200, 400 and 800 at the 1968 Mexico Games, and Ledecky matched that performance with a couple of world records as well.
Ledecky was merely racing the clock as she powered away from the field to touch in 8 minutes, 4.79 seconds, eclipsing the mark of 8:06.68 that she set at a grand prix meet in Texas back in January.
Then she waited for the rest of the field to finish.
Jazz Carlin finally touched in 8:16.17 to claim the silver, just ahead of Hungary's Boglarka Kapas, who grabbed the bronze in 8:16.37.
Some 23 seconds after Ledecky touched the wall, the last of the eight finalists finally ended the grueling race.
Ledecky was barely breathing hard.
"I hit all my goals right on the nose this week," said Ledecky, adding that her goal in the 800 free was "8:05 or better."
"I'm just proud to be part of that history."
Ledecky also became the third American woman to win four gold medals in a single Olympics, following fellow swimmers Amy Van Dyken and Missy Franklin.
Four years ago, Ledecky seemingly came out of nowhere to capture gold as a 15-year-old at the London Games. Then, after her coach moved to the West Coast, Ledecky connected with Bruce Gemmell and never missed a beat.
She called it "a testament to the vision that Bruce and I had three years ago when we set these goals, and we weren't going to stop until we met them."
On the medal stand Friday, the emotions swept over her. She broke down in tears, relishing her accomplishments and surely thinking about all the work she put in to make it there.
"The Olympics are the pinnacle of our sport, and I have to wait another four years to have that moment, and I just wanted to enjoy it," Ledecky said. "The memories mean more than the medals to me."
Hosszu got off to a blistering start and led almost the entire race. But DiRado came on strong on the final lap and beat Hosszu at the touch to win in 2 minutes, 5.99 seconds.
DiRado couldn't believe what she had done in her one and only Olympics. She put her hands on her cap in disbelief when she saw her name on top of the scoreboard.
Hosszu settled for silver in 2:06.05, and Canada's Hilary Caldwell took the bronze in 2:07.54.
DiRado, 23, already has a job lined up in Atlanta after the Olympics and made it clear she would be retiring no matter the results. She certainly has nothing to complain about after winning two golds, a silver and a bronze in Rio.
"This whole day has been kind of crazy because it's all of these little last things that I've gotten to do, like my last warm-up with the girls at the training pool today," DiRado said. "I wrote my parents an email this morning just saying thank you, and I started bawling on my bed, and then my roommates came in and comforted me. I tried to keep it all under control, but there's been a lot of tears these last 24 hours."
The Associated Press contributed to this report.