Leicester responded well, and the match turned into an entertaining, end-to-end contest for the first half hour, a pleasant change from most City matches, which typically involve their opponents putting 11 men behind the ball, merely hoping not to lose. The Algerian had been a target for Man City on the final day of the January transfer window.
But despite the prospect of banking a lower fee by selling Mahrez to a European club, Leicester are reluctant to allow Mahrez to join a Premier League rival and efforts will be made to find a buyer in Spain, Italy, France or Germany if the player can not be persuaded to remain at the club.
Yet, when Mahrez came off the bench, the Leicester fans made their thoughts crystal clear.
"My advice for the players is not to think how many games are left, just to look to the next one", he said.
Aguero punished a bad clearance from Kasper Schmeichel with a sublime dinked finish to net his 12th treble for the hosts, before saving his best until last with a dipping drive that crashed in off the bar.
Sergio Aguero completed his second-half hat-trick in the 77th minute, when the Argentine took a gift and extended the Blues' lead to 4-1. Their dominance in unrivalled in recent years, but of the four occasions they've dropped points this year, three have come since December 31, so they're not quite in the form they were last time we played.
Sen. Jeff Kruse resigns amid sexual misconduct allegations
Moore said county commissioners from Kruse's district will be tasked with choosing a replacement from within the republican party. By delaying his resignation until the end of the lawmaking session, Kruse will continue receiving his base pay and $142 per diem.
Neville launched a scathing attack on Guardiola while he was on punditry duty for Sky Sports last weekend, following the City manager's decision to name only six substitutes for their Premier League game against Burnley.
The Leicester defender will be at the centre of a summer tug-of-war between the Manchester United and City bosses.
The player's frustration is born out of Leicester's astronomical demands for a player they signed for a reported £350,000 from French second-division side Le Havre in 2014.
However, Leicester's resistence didn't last after the break as Aguero scored twice in five minutes to effectively end the game as a contest. It was a brilliant way to grab his third goal, and finished off Leicester completely in emphatic style.
Aguero still had time for a fourth, with a driving shot from range in injury time.
Another talking point from the match was the reappearance of Mahrez.