Just when it appeared Manchester United's season was lurching into a crisis of impotency, just as it seemed their Champions League future was engulfed in doubt, Wayne Rooney scored the goal they will hope changes everything. Change his own fortunes, also, as it took him level with Denis Law on 237 goals as the second-highest goalscorer in the club's history.
It came late - 404 minutes after the last United goal - with Rooney heading home from close range, with the roar of release from the home supporters not quite drowning out when they had earlier booed the substitution of Anthony Martial and chanted, imploringly, at manager Louis van Gaal and his misfiring team: "We're Man Utd, we want to attack". It was not the first such demand on a curious Old Trafford evening. It felt on the cusp.
The cry came up before kick-off, and then briefly again after just 70 seconds: "Attack, attack, attack." It was a pointed reminder, a recurring refrain in recent times from the home supporters. Nothing mutinous. Just a heartfelt plea and, at last, it felt like there was some reaction out on the pitch. More urgency, for sure there was, although maybe not a whole lot more quality.
After just three minutes Marcos Rojo's cross was only cleared as far as Rooney who snatched at his shot, dragging it narrowly wide. Then a back pass dropped short. It appeared Rooney would reach it first - but the CSKA goalkeeper Igor Akinfeev rushed to clear. Soon after Akinfeev again sprinted from his goal-line to palm the ball away from Jesse Lingard's feet after he was put through by Rooney and then alertly blocked Rojo's follow-up with his legs.
There had been a rejig of personnel by United. Most tellingly, Anthony Martial was restored to the centre-forward's position with Rooney dropping in behind him as the "No?10". It looked more balanced with Juan Mata the next to threaten as he ran onto Daley Blind's raking long ball to break the CSKA defence but, at full stretch, could not get enough power on his shot which ran through to Akinfeev.
There has been a growing sense of frustration at United's struggles. Not struggles in the sense of losing matches, playing badly, appearing disorganised. Not frustration in the sense of players being rebellious. But frustration in that the three successive goalless draws coming into this contest, the 325 minutes and counting without scoring, had highlighted sharply the lack of attacking intent that has seeped into this team, unlocking all forms of criticism.
The 1-1 draw in Moscow was the last time United had found the net and whatever Van Gaal's protestations it was undeniable that his team lack creativity, and the creative players he has have appeared to be performing as if shackled, inhibited, unable to take any form of risk. Van Gaal will point to missed chances and spurned opportunities but, frankly, there have been fewer than suggested.
So now was the time for something more. Yes, CSKA arrived with a reputation for being organised, hard to beat, on a run of 10 matches unbeaten, and 21 in all in their domestic league, but their main threat - striker Seydou Doumbia - was struggling with injury and started on the bench. How much could they threaten without him?
In truth, it was a case of weathering the storm, more of a squall, for the visitors with Bastian Schweinsteiger - alongside Michael Carrick with Morgan Schneiderlin absent for personal reasons - then earning a free-kick after being brought down as he dribbled forward. Rooney took it, Chris Smalling met it but his header bounced past the post.
Ashley Young, at right-back, was slipped a pass by Mata and crossed low across the six-yard area. It ran to Lingard. The angle was tight but he had time - but ballooned his shot over. It carried on with Rooney sending the ball wide to Young who crossed deep. There was Rojo, in a similar position to Lingard, but he slashed a volley wide.
At half-time the chants were more pointed. "Attack, attack, attack" reverberated a little more anxiously around the stadium, from both ends of the ground. That had the feel of a greater sense of frustration. It had started promisingly, at least in terms of intent, but that had subsided into a predictable ordinariness.
The most profitable avenue of attack for United continued to be down their left with Lingard then firing in low and only just ahead of Martial who had almost been released moments earlier. Martial then reached Rojo's cross but could only head weakly into the turf and up into Akinfeev's arms.
CSKA defended ever deeper. A line of four defenders on the edge of their penalty area, a line of four, sometimes five, midfielders, only a handful of yards ahead of them. United were struggling to get in behind that formidable bank of yellow with the Russians then calling on their danger man, Doumbia. Were they beginning to sense they could achieve more? Or did they reason they had to try and break out occasionally? Probably both.
He immediately provided a threat when a flick on from a free-kick dropped to him. As he ran on, fortunately for United, the ball caught between his feet and was cleared. United certainly now had something to think about as they continued to chase their desperately-needed goal.
It was with a sense of inevitability, therefore, that Van Gaal turned to Marouane Fellaini among his substitutes. CSKA were proving obdurate but were also defending so deep that Fellaini's aerial power would surely provide an obvious if rudimentary weapon. But needs must.
Mata broke through - surely. The ball ran to Rooney but he could not finish and it was cleared. Young went down. Penalty? No, dive. Carrick volleyed wide. Then CSKA broke with David De Gea saving superbly, one-handed, from Doumbia as he was clean through with Smalling blocking the follow-up on the line at full stretch. It proved vital. Carrick sprayed the ball to Lingard who carefully volleyed back across goal. Rooney met it. Finally, finally a goal.