The Argentinian striker was back from a calf strain for Wednesday night's FA Cup clash with Blackburn and he showed no signs of rust, despite an eight-game absence, as he came off the bench to net the fourth goal in City's 5-0 victory at the Etihad Stadium.
Fellow forward Alvaro Negredo had already struck twice, ensuring he moved into pole position ahead of Aguero in the race to be City's top scorer, while Edin Dzeko also netted a brace in the FA Cup third-round tie as the hosts pushed their tally to 99 goals for the season already.
After watching his team torn apart in the second half, Blackburn manager Gary Bowyer suggested City could win the Barclays Premier League, Champions League, FA Cup and Capital One Cup in Pellegrini's first campaign at the helm.
The City boss acknowledged having his triumvirate of leading strikers in such scintillating form can only aid that dream, even if it means he might have some difficult decisions over who to leave out in future.
"For me that's not a problem," he said.
"It's a problem when you don't have the players to choose. Alvaro and Edin Dzeko are in a very good moment, it's very important for the team that Sergio comes back and he scores in this game. We have so many games in the future we have no problem with the three."
Pellegrini's squad were supposed to be in Abu Dhabi this week, enjoying some warm-weather training on a mini winter break, but a 1-1 draw at Ewood Park meant they needed to finish the job at home, and book a fourth-round tie against Watford, in swirling Manchester rain instead.
However, moving to the brink of a century of goals in mid-January might have proved a more useful exercise anyway.
"You never know what would have happened if we went to Abu Dhabi," Pellegrini added.
"We had to play this game and we played well, that was very important for me. It doesn't matter against whom we play, what opposition we are playing, it's very important to keep playing the way we are playing."
Bowyer, who had suggested in the build-up he would rather Aguero played to test his young defenders, does not believe a side which had suffered just one defeat in eight prior to this contest will be demoralised by becoming the latest side to be torn apart at the Etihad.
He said: "They've learned a hell of a lot, enjoyed the challenge, enjoying playing in this arena and enjoyed playing against those players.
"They should use it as a motivation and an inspiration for the rest of the season. They should learn a hell of a lot from it."