Manchester United stole neighbours City's thunder again on Saturday when a Wayne Rooney treble inspired a 5-0 demolition of Bolton Wanderers after their Premier League city rivals had hammered Wigan Athletic 3-0 with a hat-trick of their own.
Champions United were three goals up after 25 minutes thanks to one from Javier Hernandez, making his first start of the season, and two from Wayne Rooney, who has scored in every league game this season.
Hernandez added another in the 58th minute before Rooney struck his third 10 minutes later to complete back-to-back league hat-tricks.
Like two weeks ago, when City recorded a sizzling 5-1 win at Tottenham Hotspur only to be trumped by United's 8-2 thrashing of Arsenal, Alex Ferguson's side outgunned Roberto Mancini's team to sit top of the table, above City on goal difference.
City prospered against Wigan thanks to Sergio Aguero's hat-trick. The Argentina forward has six goals in four games.
Chelsea beat Sunderland 2-1, while Arsenal recorded their first win courtesy of a lucky winner in a 1-0 victory over Swansea City. Tottenham Hotspur got their first points of the season by overcoming Wolverhampton Wanderers 2-0.
Liverpool's unbeaten start came to a halt when they lost 1-0 at Stoke City, and Everton drew 2-2 at home to Aston Villa.