The night Rooney proved he can match Europe's greatest

Wayne Rooney's face, still flushed from the exertions of an extraordinary night, broadened into a wide grin when it was put to him that he had seemed patently unhappy as crosses from his team-mate Nani floated high and wide of him a few hours earlier.

"No," he said, hesitating for an instant before conjuring an alternative explanation of his frustrations which didn't quite tally with the impression he had given out on the pitch. The dreadful first half in San Siro was a distant memory for Rooney already and he exuded the air of a player so elated by his own contribution – two headed goals were only the half of it – that he would have been happy lingering here to answer 100 questions if only the engine of the team coach wasn't running and an aeroplane standing by at Milan Malpensa airport.

It had been his finest night on the continent for United, Rooney agreed. "In the second half I got a lot more time and space to turn and run at them. I did that and it troubled their defence" – and rarely has the 24-year-old been able to say that about a European trip. His great European achievements have been largely confined to Old Trafford – the hat-trick on debut against Fenerbahce in September 2004 foremost among them – and the continental crowds who always await his arrival with a thrilled sense of anxiety and anticipation have slipped off home disappointed. Though David Beckham said in the San Siro tunnel on Tuesday night that the Italian people have developed an unexpected obsession "about whether Wayne is doing the right thing and scoring goals," his last appearance in San Siro saw him booked in an undisciplined six-minute substitute's appearance against Internazionale last February and two years before that he was a remote, frustrated figure playing in front of Ryan Giggs in the desperate 3-0 semi-final defeat to Milan.

This list of continental travails goes on. From two difficult nights at Villarreal's La Madrigal – sent off in 2005, scolded by his manager for feigning injury in 2009, to being subdued by a Sparta Prague midfield in 2004 and spurning a hatful of chances in Copenhagen two years later, Rooney has so often lacked the strength to impose himself in away games in Europe. It has not been like this in domestic competition: 49 of Rooney's first 100 Premier League goals were scored away from home, a ratio bettered only by Giggs and Frank Lampard among Premier League's centurions.

The same criticism was often meted out to Cristiano Ronaldo too, until some of those legendary displays at places like Roma and Porto in his last two United seasons and on Tuesday there was evidence that Rooney – who said in August that he wanted this year to develop from "someone who could be great" into "someone who is a great player" – has become the side's heartbeat wherever they go.

So what's changed? Confidence was the factor Ferguson pointed to in his post-match press conference and Rooney's release from support act to Ronaldo to become the central striking crux of Ferguson's team is linked to that. "I'm getting inside the box a lot more, in the six-yard box, and that's helping me score goals, which gives you more confidence," said Rooney, who had not scored in this season's Champions League tournament before Tuesday night. "That's the main thing I've been working on, so it's been worthwhile."

It is also a product of maturity and his team-mates actually learning the subtleties of how he can help them when he is the lone striker's role, by drawing defenders away to create more space behind. "The manager said at half time that when the ball comes in, the defence will try to come in with me and that's the time to turn and run at them. When the service came in, I managed to do that, push them back and give our midfielders some space," Rooney said.

The concern for those with England's interests at heart is of course that the exertions will leave him unprepared or unfit for South Africa this summer, as he has been for the last two tournaments, though Beckham raised his eyebrows when that suggestion was put. "He's only 24!" he exclaimed. "He should be able to. The way he plays on the field is the way he plays in training and that is why he is so good. Burn out won't be a problem. Wayne is ready for any game."

Michael Carrick was also discussing his team-mate before spotting the flurry of flashbulbs as the striker strode out from the dressing room and, aware that he was about to become a side show, made himself scarce. "You judge world-class players when the big games come around; how they influence them," were his parting words – and wise ones.

Wayne's world: How Rooney has found his scoring boots

* Wayne Rooney has attributed his increased goal tally for Manchester United this season – which sits at 25 following Tuesday night's headed double against Milan at San Siro – to his 'increased anticipation of balls into the box'. The forward has scored all of this season's goals from inside the area, an increase on his previous campaigns.

* United have only lost on only one occasion when Rooney has scored away from home, against Roma in April 2007.

* Prior to Tuesday's San Siro showing, the England striker had struggled away from home for United in the Champions League.

* Man United's away record in the Champions League since Oct 2004 With Rooney: P24 W10 D8 L6 F25 A18. Without: P4 W3 D0 L1 F7 A4