THE gap between Manchester City and Manchester United has been eroded this season, to the point that it is now represented by just three points.

The traditional superiority felt by those at Old Trafford has come to seem somewhat archaic, City having become the champion of the nouveau riche of modern football. They may also become the champions of this season's Barclays Premier League.

It has been an auspicious rise, one fuelled by Sheikh Mansour's willingness to burn through his incalculable wealth, making a mockery of United's penchant for belittling their rivals. The noisy neighbours are now doing a lot more than simply shouting over the fence.

They will be intent on being ungracious hosts tonight. United will make the trip to the Etihad Stadium with trepidation, the leaders having acknowledged freely the importance of this derby. Admittedly, there was little point in trying to play it down. With just two other fixtures left this season this Manchester derby has been heralded as the biggest and most important in memory, a fixture which will not only decide the destination of the league title but also where the power will reside in the English game. Goodness knows how such haughty fervour will be affected should the contest end in a drab draw.

Yet the prosaic fact is that whichever club wins will seize the initiative in the title race, with City already holding the advantage in goal difference. Should the club win to displace United at the top of the Premier League it would elicit indignation from many – City have remained somewhat unlikeable given the manner in which they have gained prominence – but they would still deserve it. United are all too aware of how dangerous City can be, just ask those that were exposed to the ignominy of the 6-1 defeat at Old Trafford earlier this season, while City have been similarly ruthless towards everybody else in recent weeks. Since losing narrowly away to Arsenal at the start of the month, City have won three matches, scored 12 goals and relegated Wolverhampton Wanderers.

It has been impressively clinical form for a side that seemed undermined by disunion earlier in the campaign. The most titillating episodes have involved Italian forward Mario Balotelli, a striker whose talent is made to compete with his foolishness. The Italian scored twice at Old Trafford and has now completed a three-match ban to return to tonight's squad. Given the gravity of the game and the intensity with which it is likely to be played you could understand were Roberto Mancini to leave him out, though.

"Mario is a player like the other players," said the City manager. "He is available for Monday and after we decide. In one game Mario can do everything. He can score two or three goals if he decides this. This is the manager's problem."

Then there is Carlos Tevez. The Argentine spent most of the season in exile but has come back to play a lead role in City's assault on the title. His presence will be to the chagrin of United supporters for obvious reasons, but he is proving invaluable to City. He has started in the last three matches and has scored four times, yet it his partnership with fellow countryman Sergio Aguero which makes him the most compelling choice to face United.

Tevez's instinct is to battle and harry selflessly, leaving his elegant compatriot to embroider a match with subtle artistry unconstrained by the need to appease him, like Aguero is obliged to do with Balotelli. Indeed, how everyone is obliged to do with Balotelli.

Mancini seemed to allude to this last week. "Carlos is not 100%, because it is impossible for him to be 100% after six months without playing," said the Italian. "But he has experience, he is a clever player. He has scored four or five goals and this is important."

It is little coincidence that a more focused City side has emerged in the absence of Balotelli. Mancini should be commended for that. The City manager has been strained by his attempt to harness the talented side of Balotelli, but he has succeeded in integrating Tevez back into the side. Doubts were cast about Mancini's ability to lead the club following his public fall-out with Tevez in Munich, murmurs which became increasingly audible with each indifferent performance. His team were winning matches but they were not always convincing, and neither was he.

Given City's owners have not been especially patient with coaches in the past, Mancini's inability to make much of an impression in Europe and unite the squad they paid lavishly for was not expected to manifest in his tenure lasting the summer months.

Yet here he is, on the cusp of wresting the Premier League trophy from the grasp of Sir Alex Ferguson and establishing prominence. The gap between their two clubs has narrowed in recent weeks, and all it could take is three points tonight to close it completely.