While Pep Guardiola's side trounced Leicester City 5-1 for their 23rd victory in 27 games, United lost 1-0 away to Newcastle United to fall 16 points behind.
Jose Mourinho has well and truly been bested, there's no question, and Gary Lineker believes that's down to two factors: Guardiola's genius and the quality of City's players.
"The reason why City are ahead of United at this moment in time is partly to do with the genius of their manager," Lineker told Planet Football, "but more importantly the fact that they have slightly better players across their team.
"Players will always make or break a manager and that will never change however good we think the managers we have in the Premier League at the moment might be.
"Mourinho and Guardiola are as good as it gets in world football in terms of coaching and tactical thinking, and it is great that we have them in our country and doing battle against each other at the top end of the table, but players will always decide whether a manager is successful or not."
Guardiola and Mourinho are unquestionably the Premier League's two finest managers, yet they're entirely unique when it comes to their managerial style.
Whereas Guardiola favours beautiful, possession football, Mourinho uses a more defensive and tactical approach.
Lineker claims he would rather watch a side managed by Guardiola - and understandably so - but he reckons there is still one area that Mourinho is top dog in.
According to the former striker, Mourinho is superior to Guardiola when it comes to working with lesser quality players and getting the best out of them, which is probably true to be fair.
"Would I rather have Mourinho or Guardiola managing my team? Now that is an interesting question," Lineker continued.
"I suspect if they were both working at the bottom end of the Premier League, Mourinho may be a little better in terms of getting results from lesser quality players.
"Could Guardiola do what he is doing now if he was in charge of Huddersfield Town? I'm not so sure and it would be fascinating to see him trying to do that.
"If he was at a club like that, he would probably pick out young players that catch his eye and develop them, but we don't know how that would work."
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