Leicester winger Riyad Mahrez, who nearly joined Manchester City at the end of January, received an ovation from both sets of fans as he returned from his self-imposed exile to make an appearance as a second-half substitute.
Claude Puel then ruled the former Le Havre man out of contention for featuring against runaway leaders City, the club he wanted to join, when speaking in his press conference on Thursday.
It became apparent from the off that Leicester were lining up with a back three in an attempt to counter the Manchester City steamroller attack, but it took just two and a half minutes for Pep Guardiola's side to find an opener.
Aguero took his tally to 13 in 10 games in 2018 with another display of clinical finishing as City went 16 points clear at the top of the Premier League table ahead of rivals Manchester United, who face Newcastle United on Sunday.
Leicester came to pick up Kelechi (Iheanacho, who signed for Leicester from City in the summer), so we did it.
Sky Sports Football Expert Jamie Redknapp hailed De Bruyne has the best ever passer in the Premier League, and Aguero says he is fortunate to play in front of the Belgium playmaker.
"In the second half, he scored four goals". He fights, he plays really good and he scored.
The City boss defended his call saying that a combination of injuries and a youth team game at the same time had contributed to his decision to travel to Turf Moor with just 17 players.
Puel said: "We need to manage this calmly".
Puel had said on Thursday that Mahrez would not play at the Etihad Stadium but named him on the bench and brought him on with almost half an hour to play, although it was to no avail as the Foxes were heavily beaten.
The Foxes defender was injured during their 3-0 victory against Huddersfield Town on New Year's Day and has been involved in training with the first-team this week, however, the match with the Citizens has come too quickly for him.