Goals from Mason Greenwood, Anthony Martial and Marcus Rashford gave United a comfortable win in the pouring rain to secure qualification from Group L.
The Reds currently sit top of the group on 10 points, two points above of AZ Alkmaar in second.
With two games to play, we are six clear of Partizan, who cannot now overtake us due to our superior head-to-head record. Our next opponents, Astana, are bottom, having failed to pick up a point thus far.
The last time United qualified for the knockout stages of this competition, we went on to claim victory in the final, against Ajax in Stockholm in 2017.