"To score three goals and keep a clean sheet, especially in a derby, is really good and I am very happy with the side," he told Sky Sports News.
"We knew that it is a good side with quality and the way that they play is quite good. But we are strong and also have quality so when we scored the first goal I thought it was a matter of time.
"They were trying to push but that gave us more space and more options on the counter-attack."
The result sees the Blues leapfrog Arsenal into third in the table.