Manchester United's Wayne Rooney (C) misses a penalty against Chelsea during their English Premier League soccer match in Manchester, northern England Sept 18, 2011. [Photo/Agencies]

Manchester United kept calmest among the "chaos" to maintain their perfect start to the Premier League season with a 3-1 win over Chelsea on Sunday in a match featuring sublime finishes and ridiculous misses.

The champions had kept up their free-scoring ways, going three goals up by halftime thanks to Chris Smalling, Nani and Wayne Rooney but the final scoreline did not reflect a game where visitors Chelsea had 21 attempts at goal.

The most awful miss came from Fernando Torres, who inexplicably shot wide in front of an open goal in the 83rd minute, somehow managing to eclipse Rooney's own howler earlier when the United striker had slipped while taking a penalty.

As Old Trafford erupted into a loud chuckle at Torres' misfortune, the beleaguered Spaniard fell to his knees unable to believe what had happened on a day where he had otherwise shown glimpses of his best and had netted his first goal of the season.

"Two of the best strikers missed crazy opportunities," Chelsea boss Andre Villas-Boas told a news conference. "It was a chaotic game."

United, who have won five games out of five, took just eight minutes to go ahead when Smalling headed in an Ashley Young free kick from the left but looked offside.

They doubled the score when Nani conjured a chance out of nothing, netting a scorcher from 25 metres out on 37 minutes after an excellent ball across the pitch from Jonny Evans.

Chelsea's coach Andre Villas-Boas gestures during their English Premier League soccer match against Manchester United in Manchester, northern England Sept 18, 2011. [Photo/Agencies]

The winger celebrated with a cartwheel and from then on United were free-wheeling as Rooney added a third on the stroke of halftime after the ball fell kindly as United took their chances while the visitors did not.

Chelsea, who had missed gilt-edged opportunities through Ramires and Torres, came out after the break knowing they needed to do something different and introduced forward Nicolas Anelka for midfielder Frank Lampard.

The substitution paid immediate dividends as the Frenchman put Torres through for a great finish with a flick of his foot as he notched just his second goal for the London club since his record 50 million pound ($78.97 million) move in January.