Mourinho told Sky Sports News: "We didn't play good in the first half. Leicester came with great defensive intensity, trying to scare us in counter-attack and we were a bit slow - slow in moving the ball and slow thinking and we needed to change and we did that.
"The second half was compete control. I don't forget they had a good chance with the result 0-0 but we had so many chances, so many opportunities to score obviously we deserved the victory."
Chelsea are currently top of the Premier League after two matches.