Oscar's first goal of the campaign after just seven minutes set the tone for the league leaders as they collected a third home win of the season.
Diego Costa added the second in the 59th minute, before Willian rounded off the victory with 11 minutes remaining.
And Mourinho was impressed with his side's efforts at Stamford Bridge, but insisted there was still room for improvement.
"I'm happy," he said in his post-match media conference. "I think in the first half we had a couple of important chances to score again but everything was under control, the team was very solid and played very well.
"I don't remember feeling fear or scared, the team always gave the feeling everything was under control.
"The second and third goal obviously kills everything but I think overall it was a very good performance.
"[But] we are not perfect, we have to improve, today we played against a good team and showed we are playing well."
The victory sees Chelsea maintain their three-point lead at the top of the table from Southampton, with defending champions Manchester City a further two points adrift.
