Manchester City boasted superior pace and purpose to go with their power, and in Balotelli and David Silva, two players who could conjure moments of magic. Manchester United's creators - Rooney, Nani and Ashley Young - were all quiet.
Superior in every department
Superior in every department
Sacked in the morning," hollered the 3,000 Manchester City fans as the minutes counted down at Old Trafford. Sir Alex Ferguson will not be dismissed today, but he will have to overcome the aftermath of his heaviest defeat in almost 25 years as Manchester United's manager.
Ferguson has enjoyed more moments than he has endured. He has delivered untold riches to United fans, but yesterday's 6-1 defeat will sit as a low point in his career.
The United fans were stunned as they witnessed the collapse. They had seen their team unbeaten at home in the previous 37 fixtures, but they were muted from the moment Mario Balotelli's 21st-minute opener slid into the bottom corner of David de Gea's net.
Before that, the 19-time English champions had been the better team and initially enjoyed the greater possession, but Joe Hart was not troubled in the City goal.
United were limited to two long-range efforts from Wayne Rooney and Anderson which Hart easily dealt with. It was a similar pattern to April's FA Cup semi-final, in which City also triumphed. United could claim to be the better team for the entire first half then, but dominance counts for nothing without a goal to show for it.
Roberto Mancini, the City manager, appeared serenely untroubled as he watched his team blunt United's limited attacks though a faultless organisation and tight man marking in their 4-4-2 formation.
Mancini has been accused of being too negative in his tactics for past Manchester derbies, when he employed a cautious 4-5-1 formation. Not yesterday.
United's up-and-coming striker Daniel Welbeck exploits space between defenders, but that space was not there to exploit and City's defence were so physically dominant that United - missing the might of centre-back Nemanja Vidic - were reduced to short corner kicks.
City boasted superior pace and purpose to go with their power, and in Balotelli and David Silva, two players who could conjure moments of magic. United's creators - Rooney, Nani and Ashley Young - were all quiet.
Balotelli is controversial and objectionable to opposition fans, the deft Silva is one of the finest talents in world football, a player at ease anywhere in his opponents' half.
The impetus shifted towards City after the opening goal, more so when Jonny Evans, the defender, was dismissed for tugging Balotelli in a dramatic start to the second half.
Old Trafford was stunned and almost silent. United fans have tasted more success than any other team in English football, but yesterday the glory belonged to their rivals.
City could easily have sat back and consolidated their lead, but they made their extra man tell, with Micah Richards, the full-back, marauding down the wing.
United tried to heed the words of their supporters who sang "Attack! Attack!" but the advances left them exposed and disorganised.
City simply picked them off and the quality of their subsequent goals was sublime.
United will be left to rue a final five minutes in which their defensive organisation just fell apart with three goals in the last four minutes giving the score line an emphatic look to City's win. The desire shown by Mancini's men to continually press forward for more goals, even though the game was won, showed a killer instinct indicative of their desire for success.
Questions will be asked about United's spirit yesterday. About their defensive frailties and the role of Rio Ferdinand. And about whether Ferguson should have bought a creative midfielder in the summer.
City have all the answers. United feared their "noisy neighbours" might claim the advantage in the title race. But nobody expected it to be so emphatic.