Both Manchester United and Leipzig came from a victory in the first round, United winning over Paris 2-1 and Leipzig defeating Basaksehir 2-0.
So it was about the team that, in case of a win, would stand alone on six points.
Leipzig performed well in a rather poor first half, and had slightly more games than the home team.
But it was Manchester United who scored the goal.
Mason Greenwood put 1-0 in the 21st minute on a pass from Paul Pogba.
After 65 minutes, Leipzig's Dayot Upamecano forced himself to his feet, after an opponent viciously knocked him down.
And it started a promotion from the home team
Rashford x 2
In the 63rd and 68th minutes, Marcus Rashford and Bruno Fernandes were substituted.
Both would be highly contributing to United's victory.
With 70 minutes played, United nearly put themselves up another goal after Bruno Fernandes came through on the left. Fortunately for the home crowd, the keeper made the save.
It got a little too long and the goalkeeper could take the ball.
Instead, the goal would come a few minutes later when Fernandes passed Marcus Rashford who free from halfway made it 2-0.
The case was wrongly ruled out for offside, but the referee changed after a VAR review.
Another couple of minutes later, Rashford got a new pass, he rounded a defender and shot distinctly 3-0.
There would be two more goals when Anthony Martial put in a penalty to make it 4-0 and Rashford had to do his hat trick.
CLIP: Dream start for Manchester United in the Champions League (October 21, 2020)
Javascript is disabled
Javascript must be turned on to play video
Read more about browser support
The browser is not supported
SVT does not support playback in your browser.
We therefore recommend that you switch to another browser.
Read more about browser support
Marcus Rashford cheers after his 2-1 goal against PSG Photo: Bildbyrån