Blues boss Sarri, who came in to replace the sacked Antonio Conte, suffered a crashing debut defeat as disappointing Chelsea were swept away by the Premier League champions.
Pep Guardiola’s side scored an early goal through Aguero, who later completed his brace after the half-time break.
However, the last side to win the Community Shield and then go on to win the Premier League title were Manchester United in 2010-11.
City’s winger Leroy Sane was substituted at half-time due to an injury, and Guardiola would be having nightmares ahead of their Premier League opener against Arsenal on August 12.
But, City dominated the game and got back in tune in an impressive way.
Manchester City are touted as the favourites to defend the title and are among the Champions league contenders following their 100-point title-winning season.
Meanwhile, Chelsea are starting to build again after chain-smoking former banker Sarri was hired from Napoli.
Sarri and Guardiola are close buddies and were spotted dining together on the eve of the Community Shield.
In the Community Shield, Aguero scored his 200th and 201st City goal, making him the first Argentine striker to hit the milestone.
The Community Shield is the official curtain raiser to the new season.