Even if Manchester United's championship ambitions have been dealt a mortal wound, there will still be nights like these, when their dominance appears total and you wonder how they could have lost one Premiership match, let alone six.
Looking at the manner in which they disembowelled Derby it was as if the dreadful, stuttering run that has scarred their season had never been. There was even the trademark last-minute goal, this one from Paul Scholes, dealing smartly with Gary Neville's cross.
Sadly for Sir Alex Ferguson, who in an impassioned article in the programme said he would not allow a lifetime's work to be frittered away, it has happened. All this victory proved was that Manchester United will retain their title if they play Derby every week.
Although he anticipated a backlash, Colin Todd claimed his team lacked the mental toughness to compete. "I am bitterly disappointed with the way we succumbed to them," he said. "They did not roll up their sleeves and when that happens you find their minds go and they stop doing the things you think they are good at."
The Derby manager admitted that his game plan was to keep things tight for 20 minutes and hope the Old Trafford crowd turned on their own team. It held good for all of 10 minutes, by which time United were two up and unveiling the kind of velvety passes across a wretchedly uneven pitch which until this season were the hallmark of Ferguson's teams.
The first breakthrough arrived six minutes into the night via a long crossfield ball from Mickaël Silvestre which Ole Gunnar Solskjaer took down on his chest and then shot on the volley past Andy Oakes, deputising for Mart Poom, who had chosen a good evening to rest a finger injury.
It was the Norwegian's sixth goal of the season, one fewer than David Beckham, who viewed the carnage from the bench. However, unlike against West Ham, Ferguson did not rest Juan Sebastian Veron and Ruud van Nistelrooy, the two most likely to inject that sliver of brilliance so obviously absent on Saturday.
Four minutes later United were further ahead as Solkjaer sent in a perfectly-directed cross which Keane, muscling into the area, drove home. Before kick-off, Ferguson had commented that he looks at his captain "and I see myself". What had first attracted him to Keane was that in Brian Clough's relegation season in 1992-3 "he seemed the only one to realise what trouble Nottingham Forest were in". In the past few disastrous weeks he has cut a similar figure at Old Trafford but last night his entire team followed him.
Frankly, Manchester United might have scored several more before the interval. Had Scholes met Veron's free-kick, floated in from the right edge of the box, with his head rather than his chest he must surely have scored. Oakes then scrambled away a deadly 35-yard drive from the Argentinian aimed squarely for the top corner of the net.
Derby were only slightly more competent after the resumption, although Fabien Barthez, who came off to rest a back injury eight minutes from time, did make a fabulous reaction save from Malcolm Christie latching on to Fabrizio Ravanelli's weary knock-down.
However, they were by then four down, which for a team that has managed three away goals all season meant further resistance was useless.
Oakes had made two fine saves from Scholes and Van Nistelrooy early in the second half but there was nothing the Derby goalkeeper could do to prevent Solsjkaer scoring a second as, from the right side of the area, the Dutchman whipped in a shot Oakes deflected crucially into the striker's path.
In the 63rd minute came perhaps United's most beautifully-worked goal of the season as touches from Nicky Butt and Scholes found Keane in the inside-right channel. His crossfield ball was met first time by Van Nistelrooy and the Derby net rippled again.
Manchester United (4-4-2): Barthez 6 (Carroll, 82); G Neville 7, O'Shea 6, Blanc 5, Silvestre 6; Veron 7, Keane 8, Butt 5, Scholes 6; Solskjaer 7, Van Nistelrooy 7 (Yorke, 78). Substitutes not used: P Neville, Irwin, Beckham.
Derby County (3-4-3): Oakes 6; Mawene 4 (Burton 64, 5), Rigott 4, Higginbotham 6, Grenet 5; Bolder 6, Ducrocq 5 (Murray 73, 5), Zavagno 4, Carbone 6; Christie 5 (Boertien, 70 5), Ravanelli 4. Substitutes not used: Kinkladze, Burton, Grant.
Referee: M Halsey (Welwyn) 7.