Manchester United moved five points clear of Manchester City with victory over Blackburn on Monday.
They could be eight points clear at the top of the Premier League by the time City kick-off against Arsenal on Sunday afternoon.
Here, Martin Hardy takes a look at how United have caught their Manchester rivals...
1. Sharing the load
In their last 11 Premier League games, Manchester United have won 10 and drawn one. In that time, 10 different players have scored. Wayne Rooney tops the list with eight during that period, Javier Hernandez has four, Antonio Valencia, Ashley Young and Danny Welbeck all have three, Paul Scholes has two, while Jonny Evans, Michael Carrick, Ryan Giggs and Dimitar Berbatov have one apiece. It is an extraordinary ability to share the responsibility.
You cannot stop United by stopping Rooney or Valencia. Sir Alex Ferguson's drive is reflected in the collective will of his players. Contrast that belief with the on-pitch unravelling of key players at the Etihad this season.
2. Big game hunters
"We have got players and a manager who have done it many times before," Michael Owen said yesterday. "People like Ryan Giggs, Paul Scholes and Rio Ferdinand have almost done it in their sleep. That is reassuring for everyone. It is one of our biggest advantages."
It has been of huge significance that Ferdinand and Scholes have returned to add stability and belief at a key time. Scholes' surprise return seems to have rattled those at City. Ferdinand has been assured and on top of that there has been the return of Valencia, another United player fearless at this time of the season.
3. The making of De Gea
How Ferguson must mock those who chase quick opinions on his signings. This has been going on since Gary Pallister was branded a waste of money soon after his £2.3m move from Middlesbrough in 1989. It is still early in David de Gea's Old Trafford career but since the turn of the year the reason why United paid £20m for him has become clear.
Key saves, notably at Chelsea and Blackburn, define seasons. They also give belief to team-mates. United have conceded eight goals in their 11-match run. De Gea has kept six clean sheets along the way, and is no longer seen as a frail, weak link.
4. The Ferguson factor
"My experience of these situations is..." said Sir Alex Ferguson after beating Blackburn. It did not matter what followed, and that the actual quote was about focusing on the next game (although that contrasted with Mancini's assertion three weeks ago that the Manchester derby would decide the title, providing evidence of a crucial loss of focus).
Much is made of mind games between Ferguson and those he takes on, but their weakness comes from within. Ferguson stands strong and does what he has always done, he leads from the front. Ferguson has taken on the richest club in the world, with two young English footballers and a young foreign goalkeeper as his only real additions.
Sometimes we underestimate the value of loyalty until Ferguson has it repaid with interest by his players as they come into the home straight.Reuse content