They had to endure a heart-stopping late scare, but Manchester United will be champions with two games to spare if Chelsea fail to beat Arsenal at the Emirates stadium this afternoon. Edwin van der Sar burnished a reputation that has suffered of late by saving Darius Vassell’s 80th-minute penalty, but the matchwinner, with his 23rd goal of a coruscating season, was Cristiano Ronaldo, who showed Vassell how to score from the spot.

Arithmetically, the destiny of the title may still be in doubt, but the way in which United and their manager, Sir Alex Ferguson, capered on the pitch at the final whistle, running to their fans in exultant celebration, said it all. They are over the final hurdle and clear in the finishing straight.

Stuart Pearce, the City manager said: “I think the result here today finishes the title race. They [United] are worthy champions.”

It was entirely fitting that Ronaldo, the footballer of the year, should score the goal that could take the Premiership trophy back to Old Trafford after four years away – appropriate, too, the way it came. The improvement in Portugal’s wizard of the dribble this season has personified United’s collective resurgence, and justice was done when, having been ruthlessly kicked by Michael Ball, he tormented his assailant into conceding the penalty which settled this scrappy derby, in which City’s approach left much to be desired.

It was not the bloodbath such games can be, but Pearce’s mediocre team sought to bridge the gulf in class with a succession of cynical trips, hacks and obstructions, nearly all of which went unpunished by the referee, Rob Styles, who had a dreadful afternoon. Not only did he miss the most blatant of illegalities, he then booked Van der Sar and Ryan Giggs for verbal transgressions, which paled into insignificance by comparison.

It was thought that Ferguson might want fresh legs after the midweek exertions in Milan, but he contented himself with recalling Rio Ferdinand and starting with Alan Smith. City were without Joey Barton, for well-documented reasons. If, as it is said, the serial miscreant’s record is the length of his arms, his knuckles must drag on the ground.

In his absence, Ball took on the role of aggressor-in-chief, and was lucky to last two minutes. Latecomers were still taking their seats when the left-back, who is on a short-term contract after leaving PSV Eindhoven, stamped on Ronaldo as he lay flat on his back and helpless. Ferguson, understandably went ballistic at the officials’ failure to spot the most obvious and outrageous of fouls. The United manager is not always the most objective of witnesses to such things, but on this occasion his touchline tirade was well justified.

How the referee and his assistant both missed the incident is a mystery, but television didn’t, and Ball is certain to be charged by the Football Association on video evidence. Putting the misery of Milan behind them, United were clearly superior from the start, and Nemanja Vidic and Ferdinand headed against the crossbar before the first half had reached its mid-point.

Michael Carrick and Paul Scholes were assertive in midfield, glad no doubt to be free of the adhesive attentions of Gennaro Gattuso. City’s anchor-man, Dietmar Hamann, is so slow these days he appears to be playing in reverse, and it was a merciful release when he was substituted at half-time. City did have chances, but their finishing was in keeping with that of a team that has not scored at home since New Year’s Day.

The decisive penalty came after 34 minutes, when Ronaldo made sure Mr Styles did not miss Ball’s foul this time, tumbling theatrically to stress his point. Not for the first time, he dived, but Pearce admitted contact was made, and not with the ball. Ronaldo dusted himself down and beat Andreas Isaksson, low to his right with dead-eyed accuracy. One goal always seemed likely to be enough.

Until the 80th minute, that is.

Then Ball, the sinner, was sinned against when Wes Brown brought him down, and Vassell stepped forward with the backing of the blue half of London, as well as Manchester. Unfortunately for City, and Chelsea, his straight-down-the-middle penalty hit Van der Sar’s legs and rebounded to safety.

All that remained was for Rooney to bring a welcome touch of humour to the proceedings. When he walked off, substituted after 87 minutes, a City fan threw a rolled up scarf at him. Rooney looked at it on the ground, picked it up up to examine it, then put it down again and stamped on it.

His team had done much the same to Chelsea’s hopes of retaining their title. For Jose Mourinho and company nothing but victory will suffice at the Emirates this afternoon if United are not to travel to Stamford Bridge on Wednesday in champagne and cigars mode. Ferguson will certainly take a glass today.

Would he be watching Arsenal v Chelsea? Definitely not, he said, he would probably play golf.

Match stats

Star man: Nemanja Vidic (Manchester United)

Player ratings: Manchester City: Isaksson 6, Onuoha 5, Dunne 6, Distin 6, Ball 4, Vassell 4, Ireland 5 (Dickov 69min), Hamann 4 (Jihai ht, 5), Johnson 5, Beasley 5 (Sinclair 61min), Mpenza 6 Manchester United: Van der Sar 7, Brown 6, Ferdinand 7, Vidic 8, Heinze 6, Carrick 6, Scholes 7, Ronaldo 7, Giggs 6, Rooney 6 (O’Shea 87min), Smith 6 (Fletcher 73min)

Referee: R Styles Attendance: 47,244

Yellow cards: Manchester City: Johnson, Dickov Manchester United: Van der Sar, Giggs

Explore Football

• Premier League

• Football League

• Scotland

• European Football

• International Football

• Live Match Tracker

• The Fink Tank

• Fantasy Football