The second of those came from the penalty spot two minutes from the end of an absorbing encounter in which Everton could count themselves desperately unfortunate. Steven Pienaar, the talented but raw South African, might find himself waking over Christmas in a cold sweat. When he flicked out his back leg to trip Ryan Giggs it was not just rash but unnecessary and, as the referee Howard Webb reached for his whistle, David Moyes could be seen placing both hands over his eyes in the manner of a child entering a fairground ghost train.
It is fair to assume Moyes was not so innocent when choosing what language to use as he asked Pienaar to explain what the Everton manager described as a "moment of madness". Ronaldo's nerveless accuracy from the penalty spot is similar to Ruud van Nistelrooy's early in his United career and Moyes did not want to watch for one reason: he, like everyone else, knew Ronaldo would score because, quite simply, English football's player of the year does not pass up opportunities to finish as the hero.
Was it coincidence that Ronaldo was the one player to miss the now infamous Christmas party? It probably mattered little but it did add to the script of another perfect day for United's No7, one in which the party organiser and serial bird-brain, Rio Ferdinand, was notable by his absence. United are famously economical with the truth when it comes to these matters but the official line was that nothing should be read into it and that Ferdinand simply had a gashed leg. True or not, Ferdinand made a point of his own - watching the match in the next seat to Jonny Evans, the 19-year-old who has been bailed by police over allegations of rape.
Ferguson, it is safe to assume, has not enjoyed the last week and, for long spells, it seemed as though Everton would subject him to an ordeal of a different kind. On the balance of possession and chances created Ferguson was entitled to say that United were the better side but their opponents ran them close at times and, after holding out for 87 minutes, it was easy to sympathise with Moyes and his players.
On the counter-attack the visitors frequently looked dangerous via Andy Johnson and Yakubu Ayegbeni and, defensively, they generally protected Tim Howard well on his first game back at Old Trafford, with Joleon Lescott outstanding.
Wayne Rooney and Carlos Tevez lit up the game only in sporadic bursts and it was easy to understand how Everton had won 11 of their previous 13 games. Ultimately, however, their determined, organised play just went even further to highlighting the absurdity of Pienaar's challenge. Ferguson described it as "amazing" and it was a moment that deserved the classic Homer Simpson "Doh!"
The only other time they let themselves down came in the 22nd minute when Lee Carsley did not get close enough to Ronaldo, allowing him to cut inside and lash a left-foot shot that dipped and swerved beyond Howard. In Carsley's defence he might not have anticipated Ronaldo would be so ambitious. Most wingers, after all, would have been satisfied putting in a cross from the position in which Ronaldo picked up the ball, on the right-hand corner of the penalty area, but this is what makes Ronaldo so special - his fondness for the unexpected and for trying things other players simply would not dare.
When Everton equalised five minutes later there was little surprise that it originated from the left flank. Danny Simpson, United's right-back, was having what can be described only as a stinker, leading to his withdrawal at half-time. Wes Brown, deputising for Ferdinand at centre-half, had gone over to help out his young team-mate when Pienaar picked up the ball close to the corner flag and, despite the close proximity of two defenders, delivered a splendid, deep cross into the penalty area. Tim Cahill had anticipated the cross and outjumped Patrice Evra and, perhaps more surprisingly, Nemanja Vidic to score his seventh goal of the season, in the process confirming his reputation as one of the more accomplished headers of the ball in the English game.
The first half had been a spiky affair, with four bookings inside the opening quarter of an hour, and it was a measure of United's frustration that Rooney spent long periods sulking about decisions or yelling at the referee. He did, however, skim the crossbar with one shot and see another cleared off the line. Yet it is Ronaldo, not Rooney, who tends to make the difference these days.