The Brazilian latched on to Marcus Rashford's pass and curled the ball beyond Aaron Ramsdale to put United a goal up in the first half.
Our new attacker is the 217th player to play for the club in the Premier League but only the 21st to find the net on his first appearance for us in the competition.
That's fitting, as of course he sports the no.21 shirt at United.
Mark Hughes was the first to achieve the feat - although he had been playing top-flight football for us since 1980. He scored in our 2-1 defeat to Sheffield United at the start of the inaugural Premier League season, 1992/93.