De Bruyne found the net four times in a 5-1 thrashing of Wolves, even imitating Haaland's famous meditation celebration pose after completing his hat trick.
"I just did it because I scored three. That never happens," De Bruyne said afterward.
Haaland will move to the Etihad Stadium in the summer after City agreed to trigger the €60 million release clause in his contract at Borussia Dortmund.
And Pep Guardiola has backed Haaland to "adapt quickly" to his style of football at Manchester City, sending a warning to the rest of the Premier League by insisting City will be even better with the 21-year-old up front.
"Big congratulations to the club, he is signed for the next years," said Guardiola.
"He is a young talented player, I'm very pleased he decided to come and join us. Next season we are going to work together and hopefully he can settle.
"We will help him to settle as soon as possible in terms of Manchester and a house. I am pretty sure he is going to adapt quickly to the way we want to play."
City have now scored 10 goals in two games since their Champions League exit to Real Madrid and sit just four points away from another title.
Following the victory at Molineux, Guardiola also had plenty of praise for De Bruyne, who scored four times inside an hour before seeing another effort come back off the post.
"I am disappointed for him because he missed the fifth goal, the post," said Guardiola.
"What can I say? The second part of the league was beyond perfect. He is always so generous and has the sense to make an assist but I think this season he also has the sense to be prolific and score goals.
"He won the game against Chelsea, he scored against Madrid. He has been decisive in scoring goals -- this is what the greatest do. I am very pleased for him, scoring four goals in the decisive part of the league is so important."
City have injury problems ahead of the trip to West Ham on Sunday.
Kyle Walker, Ruben Dias and John Stones have already been ruled out of the final two games of the season and Guardiola saw both Aymeric Laporte and Fernandinho limp off during the second half at Wolves.