Aguero’s 11th City hat-trick, and his second of the season, gave his team the three points after second-placed Manchester United had beaten Burnley 1-0 earlier on Saturday.
The Argentina striker claimed City’s first goal when he got the faintest of touches to head in from Kevin de Bruyne’s goal-bound strike, before he converted a penalty after Javier Manquillo had tripped Raheem Sterling.
Jacob Murphy pulled one back with a chipped finish over Ederson, but Aguero powerfully finished after Leroy Sane’s jinking run to seal the victory.
It was a return to winning ways for Pep Guardiola’s side after they had suffered their first league defeat of the season at Liverpool on Sunday.
City looked on course for a routine victory after dominating the first half and the early stages of the second.
As well as City’s opening two goals through Aguero, they had many other chances with the impressive Karl Darlow twice saving from Raheem Sterling, including a fine stop to push the England forward’s attempt on to the post.
Newcastle had only had 17% possession in the first half, but were given a lifeline when City lost the ball, Ciaran Clark played it forward and Murphy ran through to score a well-taken first goal for the club.
Indeed, the visitors had a chance to equalise with Ederson parrying Mohamed Diame’s effort and then the follow-up from Joselu.
But City killed off any hopes of a Newcastle fightback as Sane’s fine run saw him set up Aguero, who scored for the seventh time in five matches.
