Interim manager Ralf Rangnick saw his side put in an exciting display at Old Trafford but in the end it was only a narrow victory against the South London side.
Fred's well-struck right-footed effort was the crucial moment in the game, and the three points it yielded takes the Reds up to sixth in the Premier League with sights set on climbing higher still.
The 28-year-old's goal drew jubilant celebrations from his United team-mates, all of whom were delighted to see the popular character get his moment in the spotlight.
"It’s always good to score in a game, but today we win 1-0 and it’s nice that my goal can be so important," a beaming Fred told club media's Stewart Gardner.