Heung-min Son struck the only goal of the game on Monday night.
Mourinho says it was a triumph thanks to a united squad: “All of them did their jobs in a very difficult match.
“It's not the football we want to play, but it's the football that Burnley push you to play and if you don't cope with it, you are in trouble.
“It's a team, it's the feeling of a team and I felt that even when we 'lost' against West Ham. We 'lost' against West Ham - I like to say that. Even when we 'lost' against West Ham, I felt that the team was there, and the team felt the pain together and coped with the pain together and today, when we were 1-0 up, I felt calm, I felt that the spirit was there."