The Red Devils made it two wins on the bounce in the Premier League with an emphatic win at the Liberty Stadium.
Mkhitaryan was instrumental providing two assists to his team-mates.
Goals from Eric Bailly, Romelu Lukaku, Anthony Martial and Paul Pogba wrapped up the impressive win.
Mkhitaryan said: “It was a tough game, especially in the first half.
“We had passion, we did what we had to do.
Manchester United: Team average – 7.71
“We also have a little luck with the chances we are creating”
Man Utd ace Henrikh Mkhitaryan
“The second half became much easier because they played with more defenders and that left space.
“Team spirit. We also have a little luck with the chances we are creating.”
United could have been behind early when Jordan Ayew hit the crossbar but from then on the Red Devils took control.
Next up for Jose Mourinho’s side is a home clash against Leicester in the top flight next Saturday.
Mkhitaryan will hope to continue his fine form against the Foxes.