Argentine striker Aguero netted all his goals in a devastating second-half showing - twice finishing from Kevin de Bruyne's flawless passes, punishing a Kasper Schmeichel error by chipping into the net and curling in a sublime fourth.
City bounced back from their disappointing draw away to Burnley last weekend with the resounding win against Leicester. Riyad Mahrez even made an appearance off the bench for Leicester, and Kevin De Bruyne was sensational yet again.
A source has told ESPN FC that Mahrez remains determined to leave Leicester at the end of the season, with the player believing that he has been loyal to the club since helping them to their surprise Premier League title success in 2015-16.
Nicolas Otamendi's wayward pass got to the feet of Jamie Vardy, who charged up the midfield, beat a lunging Ilkay Gundogan and slotted a shot through the legs of Aymeric Laporte and into the back of the net.
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The 31-year old fired the ball between his legs and past Ederson into the far corner, with the ball taking a slight deflection off the French defender on the way through.
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Leicester made a change at half-time, bringing on Danny Simpson in a change of shape intent on disrupting the predictable style of the game.
"I don't know (which was my favourite goal) - maybe the last one because it's a long time since I scored from outside the box".
De Bruyne set up another for Aguero just five minutes later, this time capitalizing on a poor clearance from Schmeichel to feed the Argentine forward.
Aguero has 12 hat tricks during his City career.