Before he stepped to the plate to face Yankees left-hander Tyler Lyons in the bottom of the 12th inning, the 21-year-old rookie told his teammates in the dugout he'd hit a homer against the southpaw.
"Before the at-bat, he told a guy on the bench, 'If they leave the left-hander on the mound and he throws me a slider, I'm going to take him deep," manager Charlie Montoyo said of Bichette, according to MLB.com's Keegan Matheson.
Bichette stuck to his word and drove a 1-1 slider from Lyons over the left-field wall for the game-winner.
''I've never done that in my life at any level,'' Bichette said, according to The Associated Press.
''I just had a feeling. I was seeing the ball real well all day.''
With the home run, Bichette became the youngest Blue Jays player ever to hit a walk-off homer, according to the team.
Bichette has been on a tear since arriving in the big leagues at the end of July, hitting .313 with a .945 OPS, 11 homers, and 17 doubles.