Seven-time Olympic gold medalist Katie Ledecky continued her domination in the pool on Tuesday night, after extending her win streak in the 800-meter freestyle to 12 years and beating out her closest opponent by more than 19 seconds at the U.S. Swimming Championships in Irvine, California. 

Ledecky, 25, finished her first event of the five-day competition with a time of 8:12.03 — beating out second-place finisher Kensey McMahon by a whopping 19.89 seconds. The 800-meter free is Ledecky’s trademark event as she owns 29 of the fastest times in the event’s history, according to NBC Sports. 

Katie Ledecky swims past an opponent in the 800m free

Katie Ledecky swims in the Women's LC 800 Meter Freestyle Final during day one of the 2022 Phillips 66 National Championships in Irvine, Calif., on July 26, 2022. (Sean M. Haffey/Getty Images)

"I’m happy with that," she said, according to the outlet. "I didn’t really have any expectations coming into this."

KATIE LEDECKY WINS 800 FREE FOR FIFTH CONSECUTIVE TITLE AT WORLD SWIMMING CHAMPIONSHIPS, SWEEPS FOUR EVENTS 

Ledecky holds the world record in the 800-meter free with a time of 8:04.79, which she set with her gold medal run at the 2016 Summer Olympics.

Katie Ledecky reacts to winning 800m free

Katie Ledecky reacts after winning the Women's LC 800 Meter Freestyle Final during day one of the 2022 Phillips 66 National Championships in Irvine, Calif., on July 26, 2022. (Sean M. Haffey/Getty Images)

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Her win on Tuesday follows a successful run at the world swimming championships last month, where she won all four of her events, including the 800m free, for her fifth consecutive title at worlds and eighth consecutive including Olympics finishes. 

Ledecky has the most medals for a female swimmer in world championships history with 22, including 19 gold. Only Michael Phelps, who won 26 gold, has more.

Katie Ledecky swims past an opponent in the 800m free

Katie Ledecky swims in the Women's LC 800 Meter Freestyle Final during day one of the 2022 Phillips 66 National Championships in Irvine, Calif., on July 26, 2022. (Sean M. Haffey/Getty Images)

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Ledecky will be competing in the 200m free on Wednesday as well as the 400m individual medley on Thursday.