A snap decision led to a big catch.

A valiant lifeguard plucked a massive alligator snapping turtle from the waters of a Washington state park — then posed triumphantly with the invasive creature.

The exotic species, the largest freshwater turtle in the US, was found under a dock last week at Juanita Beach Park in Kirkland, a Seattle suburb located on the eastern shore of Lake Washington, according to Kirkland Parks and Community Service.

The exotic species, the largest freshwater turtle in the US, was found under a dock last week at Juanita Beach Park in Kirkland. Kirkland Parks and Community Services

“While they may look interesting, snapping turtles are invasive and can be aggressive,” the park service shared in a Facebook post Monday.

“Their powerful jaws can cause serious injury, so if you see one, please keep your distance and alert a lifeguard or park staff.”

The park is located in a Seattle suburb on the eastern shore of Lake Washington. Mauro – stock.adobe.com

Kirkland lifeguard supervisor Dani pictured hoisting the hulking dinosaur-like reptile. Kirkland Parks and Community Services

Photos showed Kirkland lifeguard supervisor Dani hoisting the hulking dinosaur-like reptile as it bared its snarling jaws wide open.

“Thanks to Dani, our lifeguard team, ACO Arnold and Washington Department of Fish and Wildlife for keeping the beach fun and safe for everyone!” the government agency said.

The ferocious prehistoric-looking turtle, with its spiked shell, beak-like jaws and primitive face, is considered an invasive species and is prohibited in Washington state.

The beastly species — found in rivers, canals and lakes in the southeastern US as well as in Central and South America — can live up to 100 years, grow as long as 6 feet, and weigh as much as 220 pounds, according to National Geographic.

The carnivorous creature also has a voracious appetite and boasts a vicious bite — packing about 36 pounds of force, enough to crush bone.

It remains unknown where the turtle came from or what its fate will be now that it’s been caught.