The Uruguayan volleyed home on six minutes after a nice move involving Alex Telles and Paul Pogba to net his 50th goal in European competition.
David De Gea made a couple of excellent stops after the break, before a Jesus Vallejo own goal, as substitute Juan Mata went for a header, ensured a comfortable win for Ole's men.
The Reds will now face Roma in the last four of the Europa League after their 3-2 aggregate victory over Ajax.
You can watch highlights from Old Trafford above and see reaction from Ole and Bruno Fernandes below.