Ole Gunnar Solskjaer's side totally dominated throughout the 90 minutes at the AMEX, finding their opener after just 16 minutes through Mason Greenwood.
The 18-year-old took his tally to 13 for the season when he deceived Lewis Dunk with some neat footwork before finishing neatly at the near post.
Fernandes grabbed his first after 29 minutes via a deflected strike, adding another early in the second-half with a fine volley.
Paul Pogba started in midfield and was impressive with a poised performance alongside Nemanja Matic.
The win puts United back into fifth above Wolves on goal difference, and Solskjaer was a happy man after the final whistle.
"It's a joy to watch them when you see them express themselves like that," the Norwegian said.
"The confidence comes from performances and knowing they've done the right things leading in to the restart. They worked hard during the lockdown and we know we have loads to play for.
"The third goal was a great team goal. To see so many players sprinting forward to get on the end of it was fantastic. A great finish by Bruno Fernandes.
"Paul Pogba was top. He got hold of the ball, sprayed it, won headers. He's just going to get better and better."