Cech hailed Chelsea's "brilliant mentality".
Cech told Sky Sports: "We were very good, we put them under pressure, created chances and converted them clinically.
"From 2-0 we controlled the game and with a few more mistakes from them under pressure, we scored more goals and 5-0 is a good result.
"We knew it was not going to be easy if the mentality was not right and the mentality was brilliant, that's why we made the game look easy.
"At 5-0 up and controlling the game, we didn't allow them to come into the game and score a goal. It is always important to kill the game off and keep a clean sheet."