The Old Trafford side had to repel a constant wave of pressure and possession from the German visitors, up until Rashford, off the bench, ran through to score the second goal on the counter-attack.
From then on United were ruthless with their fast-paced attack and clinical finishing, as Rashford scored three and passed on a penalty which Anthony Martial scored instead, adding to Mason Greenwoodâs first-half goal.
Rashford says the squadâs mentality and Ole Gunnar Solskjaerâs instructions to keep on attacking were key to the eventual 5-0 win over a team which reached the semi-finals of the competition just a few months ago.
âThe manager told us when we come on to up the tempo,â Rashford told BT Sport.
"There were definitely spaces there, we got Bruno [Fernandes] and Paul [Pogba] on the ball and Anto [Anthony Martial] running forward - we looked dangerous every time.
âIt was a team performance. The ones who started did well and the ones who came on did well too. We canât ask for more than that, just intensity and attitude to kill the game off.â
The crucial second goal was initially given as offside, with the assistantâs flag going up as soon as Rashford ran through from the halfway line - but a VAR review showed he was just inside his own half when the pass was made, meaning the goal stood. The striker says he knew it would count and he had to ensure he finished the move, while also now urging focus on Unitedâs weekend clash with Arsenal.
"I thought I was in my own half so I was confused when the flag went up; we have to work with VAR, itâs part of the game now so the quicker we get used to it the better.
âItâs about the next game now and itâs important for us to get three points in the league.â