Ronaldo produced a wondrous free-kick on the hour to send United eight points clear at the Barclays Premier League summit after Roque Santa Cruz had scored for Rovers, ending United's barren run at 1,334 minutes.

 Big Sam and Fergie agree to disagree

But visiting boss Sam Allardyce was left cursing referee Howard Webb for his failure to award a penalty when Rafael Da Silva appeared to foul Morten Gamst Pedersen as Rovers remained in the relegation zone.

Having gone so long without conceding, it must have been pretty galling United should lose their record in such a self-inflicted manner.

First, Nani and Paul Scholes waited for each other to collect a loose ball on halfway, allowing Andre Ooijer to step in and dart forward.

After beating Patrice Evra, Ooijer then slipped a pass to Santa Cruz. With Rio Ferdinand closing in on the South American, there was little need for Tomasz Kuszczak, standing in for the rested Edwin van der Sar, to dart out.

The situation still seemed to be under control. But both United players then committed themselves to a tackle, allowing Santa Cruz to calmly continue his run and tap into an empty net.

It was a run that had to end at some point of course. And at least Ferguson had the consolation of knowing his side had previously gone in front through Wayne Rooney.

The England striker had scored with his first touch following his return from a hamstring injury against Fulham on Wednesday.

Handed a start in order to prove his fitness ahead of the meeting with Jose Mourinho's Inter Milan, Rooney was buzzing about in his usual manner. And when Ryan Nelsen stretched to reach Nani's cross and succeeded only in prodding the ball slightly nearer his own goal, Rooney gleefully finished.

Nelsen had already saved a certain goal when he hooked the ball away from Michael Carrick's head as the England man arrived at the far post in the expectation of finishing off Ronaldo's cross.

Still, the hosts thought they had regained the initiative at the end of the opening period when Jonny Evans - selected ahead of Nemanja Vidic, like Van der Sar an ever-present during the previous 14 games but banned for the San Siro trip - rose to power home Nani's corner.

Referee Howard Webb detected a push, either from the Northern Ireland international or Ronaldo just in front as a group of players jumped. It seemed a very harsh call at the time and TV replays only backed up that opinion.

If Nelsen had seen his shot fly in instead of bouncing back off the post, Ferguson would have been complaining bitterly.

Instead, with El-Hadji Diouf firing the rebound straight at Kuszczak, United were soon celebrating.

The Red Devils have been waiting for a spectacular Ronaldo free-kick for about the same amount of time as their goal has been boarded up. Having lost out at one end, Ronaldo did the business at the other.

Paul Robinson must have been expecting a cross after Keith Andrews had sent Patrice Evra flying on the left edge of the box. Instead, the former England goalkeeper was beaten by raw pace as the ball flashed into the roof of his net.

Having lost one lead, it seemed unlikely the hosts would do it again.

Yet Rafael Da Silva was incredibly lucky to escape when he put his hands on Morten Gamst Pedersen's shoulders in an attempt to get into a tackling position as the Norwegian burst into the box.

Pedersen went down. Webb said no. On the touchline, Allardyce erupted in a rage and got involved in a heated exchange with Ferguson, with whom he had shared a convivial post-match drink at the same ground on Wednesday.

The departure of Evans straight after Ronaldo's blinding effort was a major concern, with Vidic suspended for the Inter clash.

Carlos Tevez's introduction at the same time was a reminder of the strength within Ferguson's squad, even if the Argentina forward is starting to mull over his long-term future.

Yet nowhere else, with the possible exception of Barcelona, would Tevez get to figure amongst such a dazzling array of attacking talent.