Zlatan Ibrahimovic bagged a brace before Dejan Stankovic and surprise starter Victor Obinna rounded out the result.
Mourinho said: “It was the best Inter performance of the season and we dominated for the whole match. We did very well and I think the team showed a lot of intelligence to interpret the game and I am very happy,” he said of the triumph away to Roma.
“A 4-0 scoreline in a big game like this and with that kind of performance is an important result indeed.
“Ibra always tries to find space between the lines. He can play in any tactical system, can be a centre-forward with the team supporting him by pushing up the field. He is a real team player and I think he is very important for Inter.
“I picked Obinna because I have been working with these players all week, as the others were away on international duty,” explained Mourinho.
“I knew it was crucial for Stankovic and Sulley Muntari to close up on Alberto Aquilani and Daniele De Rossi, not giving them the chance to express their quality.
“Stankovic is a great player and did well today, as he and Muntari were decisive in putting pressure on the Roma midfield.
“I was not afraid of fielding a very high defence because I knew the midfield movement would protect them and allow this system.”