Fernandes took advantage of a poor strike from compatriot Joao Palhinha and, seconds before the end of added time at Craven Cottage Stadium, shot into the bottom corner from the edge of the area.
United bounced back from their defeat with the scoreline ofe on the game, as he almost connected on a free kick before it fell to Garnacha.
After a sluggish first half, Fulham added to their lead after the break and took the lead.
