Sead Haksabanovic made it 2-1 to Celtic with a cool finish. The Montenegro Internationalist guided a driven effort low into the net, with the aid of the post.
Earlier, Haksabanovic had scored his first goal for the club with a tap-in from a cross from Jota. He will be hoping to complete the hat-trick as Celtic look to take a stranglehold of the game.
The delays from VAR checks have benefitted the visitors as United have been able to catch a breath and break the rhythm of the Scottish Champions.