When Jacob O'Connor found two-year-old Dylan floating face-down in the swimming pool he didn't rush off and find a grown up to help, instead he remembered a move from one of his favourite films, San Andreas.
Jacob, from Roseville, Michigan, managed to pull his brother out of the pool and started giving him chest compressions - just as he'd seen The Rock doing in the film.
Dylan was then rushed to hospital and went on to make a full recovery.
When he heard of Jacob's amazing intervention, Dwayne Johnson tweeted: "Wow amazing story....You're a real life hero. We're all proud of you! DJ".
Jacob's mother Christa O'Connor told the BBC: "I'm at a loss for words. I'm amazed at what Jacob did. I'm so proud of him."