The Welsh winger continued Spurs' ongoing celebration wars after scoring a dramatic stoppage-time winner to deny the Seagulls.
Johnson smashed home Heung-min Son's low cross from close range in the sixth minute of added time in the club's 2-1 comeback victory.
As well as helping Ange Postecoglou's men back into the top four, the goal also exacted revenge for the 4-2 defeat Tottenham suffered in the reverse fixture at the Amex earlier this season.
Joao Pedro bagged a double as Brighton raced into a four-goal lead in that game and he taunted Spurs by holding up four fingers to the camera in his celebration.
The Brazilian missed out on the return match in north London this weekend, but Johnson made sure to send a message anyway.
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Despite only scoring Tottenham's second in the game, the 22-year-old held up four fingers across both hands as he wheeled away.
And fans were loving the gesture, with one writing: "Bro bookmarked the celebration."
Another said: "Nah I didn't even notice this COLDDDD."
A third added: "Wait did Brennan Johnson do the Joao Pedro celebration when he scored the winner???? He might be the greatest of all time."
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The celebration dig comes after Johnson's teammate James Maddison was involved in a similar spat with Maupay last month.
The Frenchman wound up Tottenham fans by doing Maddison's darts celebration after scoring in Brentford's 3-2 defeat.
England star Maddison ultimately had the last laugh but a war of words between the pair later broke out on social media.
However, Postecoglou has already made his feelings clear on his players becoming too caught up in play drama.
Asked if Maupay's actions had been added motivation for his team, the Australian replied: "I hope not because that's exactly what I'm talking about.
"I'm not a fan of it, I don't like the whole bravado, pushing people around. If you're that brave about things, my players and their players, get into a UFC cage and I'll see how brave they are.
"We're out there to play football. And that's what I want our guys to do, focus on playing football.
"And they shouldn't get motivated by things that aren't really that important to us."