A major talking point of the game came in the 37th minute when Liverpool's Sadio Mane was shown a straight red card by referee Jon Moss for a studs-high challenge on City keeper Ederson, who was stretchered off after a lengthy delay.
City were already 1-0 up at the time and De Bruyne was full of praise for the way his team-mates made their one-man advantage tell.
"Obviously we knew it was going to be a very intensive game. They are very strong offensively and for the first 20 minutes it was a bit back and forth all the time," said De Bruyne.
"After the first goal we took control and then that (the sending off) happened. It was not a bad foul but with the way Eddy comes out of it its normal for a red card.
"If he doesn't have the injury it's a yellow card.
"After that I think we played really smart. We didn't give Liverpool time and if you score a few goals it makes it a lot easier."
With the fixture calendar set to intensify after last week's international break, De Bruyne says the manner of the way City put a high-flying Liverpool to the sword will fill the squad with confidence.
"I think it was good to score a lot of goals. Obviously, it was different with them playing with 10 men and you have to keep your shape and be very focused," De Bruyne added.
"I think it's very good for the guys to get another game under our belt as the calendar is getting very busy so everybody will play."
It was also a memorable game for Sane, who made a major impact off the bench by scoring two second half goals, the second a superb curling effort from 25 yards out.
"We have a very good team with top players. I wanted to use my chance today and it was a good day for me," the German reflected.
"And I especially enjoyed the second goal!"