The Blues never recovered from going behind early in the game and were largely outplayed by a Foxes side that now go six points clear at the top of the Premier League.
Only Liverpool have handed out similar punishment on City’s own turf and too many of the home side had a bad day at the office.
If there were any doubters in the record 54,693 Etihad crowd as to why Leicester sat three points clear at the top of the Premier League going into this clash, they were dispelled in the opening few minutes.
Quicker to the ball, pressing with aggression and dangerous in the attacking third, the Foxes were ahead inside three minutes.
Riyad Mahrez dashed down the right, skipping past Aleksandar Kolarov before being fouled by the Serbian on the edge of the box.
A simple cross into the six-yard box seemed to catch the Blues off-guard and burly defender Robert Huth was first to react, poking a deflected shot towards goal that left Joe Hart stranded.
It was exactly the start City had needed to avoid with the Foxes expert travellers on the road and having lost just once in their previous 15 away games
...City 1 Leicester 3...
It also allowed the visitors to regroup, defend in numbers and invite the Blues to come on to them – a task they did comfortably for the majority of the opening period, twice coming close to doubling their lead in the process.
Things could have been different, however.
City had two good shouts for a penalty – the first on 24 minutes when Pablo Zabaleta was brought down on the right of the box with TV replays showing the infringement had been on the line and perhaps should have resulted in a spot-kick.
The second shout was on 41 minutes when Fernandinho was shoved to the ground in the box – the kind of foul that is given anywhere else on the pitch but more often than not when it means a penalty being awarded.
The Blues went in at the break having dominated possession but having failed to really threaten the visitors where it really counted. It seemed Manuel Pellegrini would need to have a rethink during the half-time break in order to find a way back into this match.
Unfortunately, City hadn’t the learned the lessons of the first half and again, with three minutes of kicking off, Leicester had increased their lead after breaking at speed and Mahrez skilfully skipped a challenge before wrong-footing Hart with a powerful drive.
On the evidence to that point, it seemed as though it was game, set and match in favour of the East Midlands side. Pellegrini replaced Toure and Delph immediately after the goal with Fernando and Kelechi Iheanacho coming on.
Fernando came close to scoring within a few minutes, too, as he headed a corner towards goal but Kasper Schmeichel made a fine save to preserve his side’s two-goal advantage.
It got worse for the Blues on the hour-mark when Huth scored his second of the afternoon, rising higher than anyone else from Christian Fuchs’ corner to head firmly past Hart and effectively end the contest.
Aguero headed home a consolation goal with two minutes to go, glancing home Bersant Celina’s fine cross and might have had another a minute later when he intercepted a poor back pass - but he fired wide from an acute angle.
In truth, it was too little too late on a day when the hosts were second-best in all departments.
An afternoon to forget and with Spurs up next weekend, the Blues need to move on and regroup as quickly as possible.
