Anthony Martial broke the deadlock in the 30th minute and Scott Mc Tominay locked the match in favour of the hosts in the stoppage time, 90+6 minutes to be precise.
In the 17th minute, Bernardo scored a scintillating opener and then threaded the pass that led to Riyad Mahrez doubling the lead.
The City have looked short on quality defensive options and seems like they have made their mind to invest in the same department.
After a brilliant first half on offence and the following half marked by their iron-clad defence, the Red Devils ultimately emerged from the Etihad Stadium with a terrific 2-1 win against City.
Comments from Gary Neville come after a spectator was accused of hurling racist abuses towards Fred at the Etihad Stadium during the Manchester Derby.
The incident happened in the second half of the Manchester Derby when the Brazilian footballer Fred went into the sidelines of United's half.
Also, see Manchester City vs Manchester United, Premier League match prediction, live streaming details and when and where to watch in India.
Anthony Martial, though not a definite starter, will play his part in the match.
This season is tough for Guardiola's men as they might fail to defend their Premier League title, courtesy the form of table-toppers Liverpool.
Pep Guardiola has opted to rest some big names, with one eye on a midweek continental fixture with Liverpool, for Saturday's blockbuster tie.
