While filming "Avatar: The Way of Water," Kate Winslet did the unthinkable. 

Not only did she deprive herself of air for over seven minutes, she broke a record previously held by Tom Cruise.

"Straight away I wanted to know my time," Winslet told Total Film Magazine.

Winslet held her breath for seven minutes and 15 seconds. Cruise's record for "Mission: Impossible — Rogue Nation" was six minutes.

Kate Winslet in a sparkly black dress for the 'Avatar' red carpet split Tom Cruise in a black shirt looking off to his right

Kate Winslet recently broke Tom Cruise's record for amount of time spent without air. (Dave J Hogan/The Chosunilbo JNS)

SIGOURNEY WEAVER TRAINED LIKE A NAVY SEAL TO HOLD BREATH UNDER WATER FOR 6.5 MINUTES IN NEW 'AVATAR' FILM

"I have the video of me surfacing saying, 'Am I dead, have I died?' And then going, ‘What was [my time]?’" she shared.

"I couldn’t believe it.

Kate Winslet in a black matching suit set and white top on the "Avatar" blue carpet

Kate Winslet reunited with "Titanic" director James Cameron to make "Avatar: The Way of Water." (Tristan Fewings)

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"The next thing I say is, ‘We need to radio set.' I wanted Jim [James Cameron] to know right away."

She added that she didn't have to hold her breath for that long, but "I wanted to break my own record, which was already six minutes and 14 seconds. And I was like, 'Come on!' So I smashed my own record by a minute," she told the outlet.

"She's not competitive at all," director James Cameron joked.

Kate Winslet holds on to James Cameron on the "Avatar' blue carpet as the two break out into a laugh

James Cameron joked that Kate Winslet isn't competitive. (Dave J Hogan)

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Winslet reunited with her "Titantic" director for the latest "Avatar" installment, and she was thrilled to be working alongside the acclaimed director again.

"It was just so flattering that Jim asked me because Jim does not suffer fools," Winlset said.