The youngster took advantage of Svilar's weakness under the high ball to give United the lead with just the game's third shot on target.
Rashford lined up a free kick from deep on the left and opted to firing it over the heads of everyone in the middle to test out the young goalkeeper, who became the youngest goalkeeper in Champions League history by starting the game.
The test worked, with the 18-year-old only managing to carry the ball into the back of his own net as he desperatley backpedalled.
Check out the goal for yourself below.
Rashford goal if you missed it #BENMUN #rashford
— RED DEVIL REPORTS (@RedDevilReports) October 18, 2017
pic.twitter.com/oUrpBfwEtC