Almost halfway through the Premier League season and there is already seven points separating Manchester rivals City and United from the chasing pack.
"At this point in time everyone thinks it is going to be a one-two for the city (of Manchester)," United manager Alex Ferguson said Friday. "But things change. You only need to go back over the years to see how dramatic our league can be. Lose a game in this league and all the rest get a pickup and start chasing harder."
After a glut of goals in the opening four months of the season, it is Ferguson's rivals across Manchester entering the packed Christmas fixture program as the top team in England for the first time since 1929.
Back then, Manchester City failed to stay the course, taking until 1937 to win the title and 1968 to repeat the feat.
This time, another slip-up would be unacceptable for City's owners after an expensive overhaul of the squad over three years.
But City has displayed resilience since exiting the Champions League and losing for the first time this season at Chelsea, bouncing back with successive Premier League wins to establish a two-point lead over Manchester United.
Ahead of Monday's match at West Bromwich Albion, City has already scored 53 goals in 17 league matches - more than twice the haul at this stage a year earlier.
"Last season we got a lot of uncalled-for negative publicity because the goals weren't flowing freely," City defender Joleon Lescott said. "But this year we have the belief and the confidence to score more goals.
"We did need to change and there is an air of confidence about us now. But it is controlled, you don't want it to be too arrogant. The main thing is to keep progressing and keep our feet on the ground."
It is two years since Roberto Mancini replaced Mark Hughes as City manager. Having already ended the club's 35-year trophy drought by lifting the FA Cup in May, the focus is firmly on delivering the club's first league crown since 1968.
"We need to win away games," Mancini said. "We have only one point from our last two."
Stumbling at West Brom could allow United to go top with a win over Wigan on Monday. The champions are maintaining the pressure on City despite a series of setbacks this season - including Champions League elimination and a humiliating 6-1 loss against its neighbor.
"We have shown the resilience and determination to do something about it each time (a setback) has happened," Ferguson said. "That says a lot about the character of the team. We lose games in normal seasons.
"This season we have lost games that have been dramatic and a bit more emphatic in the sense of the impact it had on our chances of winning trophies. These were bad results for us but the character of the team has rescued us each time."
The Manchester teams have ended the week further ahead of their title rivals after Tottenham drew 1-1 with Chelsea in the clash of third and fourth.
Tottenham is seven points behind United and a further two adrift of City with a game in hand, while Chelsea is two points further back in fourth.
But Tottenham's injury crisis deepened in Thursday's draw with Chelsea as playmaker Rafael van der Vaart sustained a hamstring problem - like four teammates - that is likely to rule him out until January.
Winger Aaron Lennon was injured against Sunderland on Sunday and is likely to be out for the club's next three games, while defenders Ledley King and Younes Kaboul both hurt their hamstrings against Chelsea, the latter in the warmup.
While striker Jermain Defoe also missed the London derby, he could be fit for the trip to Norwich on Tuesday to help Tottenham close the gap on second-place United.
Arsenal is struggling to break into the top four and its defensive troubles have been compounded by Kieran Gibbs undergoing surgery on his left groin and being ruled out for another month, having already been sidelined since October.
Arsenal hosts Wolverhampton Wanderers on Tuesday in a match pushed back 24 hours due to a strike by public transport workers in London.
In fixtures still going ahead on Monday, Newcastle is at Bolton looking to end a run of six games without a win, Liverpool hosts bottom-place Blackburn still mired in controversy over Luis Suarez's ban for racially abusing an opponent, Everton goes to Sunderland and Stoke takes on Aston Villa.
Two of the promoted sides meet on Tuesday when Swansea hosts Queens Park Rangers.