Manuel Pellegrini's side then added two more goals in the second half through big-money summer signings Cristiano Ronaldo and Karim Benzema - on his 22nd birthday - to record their biggest win of the season.
Pellegrini will also have been delighted to see his team keep a clean sheet in their first match without influential centre-back Pepe, who is set to miss the rest of the season through injury. He said, "We need to do this consistently.
"We played ninety solid minutes, with intensity. We maintained our defensive security, and tried to score as many goals as possible.
"Now we have to maintain this for the rest of the league."
Pellegrini made sure not to get too carried away, continuing, "It is difficult to jump to conclusions in football.
"The team has confirmed its good form. I am happy because they played well and scored good goals.
"The scoreboard suggests a perfect match. We have tried different formations, and rotations. The points and performance indicate that we are succeeding. The players have understood the message.
"I do not know if it is perfect, but we are on the right track."