Vincent Kompany had been here before. A must-win Monday night fixture in a thrilling Premier League title race with all eyes on the Etihad.
April 2012. Kompany's giant leap and winning header here in a titanic Manchester derby gave City the points against United and the momentum to become champions under Roberto Mancini.
But who could have believed that seven years on he would produce this?
City were staring down the barrel when the ball reached Kompany 25 yards from goal in the 70th minute.
He was just about the last person on the pitch you expected to try his luck from that distance but the connection was sweet and the outcome quite stunning.
It screamed into the top corner of Kasper Schmeichel's net and the Etihad screamed with it.
It was the ultimate justification for Pep Guardiola's decision to play his captain ahead of John Stones and Nicolas Otamendi, who were both on the bench here.
Some may have seen it as a gamble to put Kompany up against the pace of Jamie Vardy, but it just underlined Guardiola's trust in his captain.
Even Guardiola couldn't have hoped for it to turn out like this though.
Kompany turned 33 last month and this was only his 12th league start but, more significantly, his third in a row. With Stones out of form and Otamendi out of favour, he is currently the partner for Aymeric Laporte.
He was called into action as early as he eighth minute here when Ricardo Pereira – scored of the late winner when City lost at Leicester on Boxing Day – skipped inside Laporte whose flailing challenge could easily have resulted in a penalty.
Pereira, to his credit, was more interested in scoring. He stayed up and had a clear sight of Ederson's goal. He took aim and hit the ball well enough but Kompany threw his body in front of the ball in a blur to make a quite magnificent block.
On what was always going to be a nervous night at the Etihad, some of his teammates were clearly feeling the pressure. Shots flew into the stands behind Schmeichel's goal, and one from Kyle Walker even made it high up into the second tier.
But Kompany remained unflappable, strutting around like he does as the last line of defence, an old head and calm presence at the back.
When he was forced to extend himself, turning to chase Vardy back towards his own goal, he still had enough pace to match the England strike stride for stride.
It wasn't always so straightforward. When Laporte's poor header allowed Leicester to break on halfway just before the interval, Kompany was forced into another lunging challenge on James Maddison.
He got a touch on the ball before upending Maddison but not enough for Mike Dean's liking and the yellow card came out.
Just as he did in the Old Trafford derby two weeks ago, however, Kompany didn't let the booking affect his game. If anything, he became even calmer and more measured.
It's one of the reasons Guardiola is so keen to keep the Belgian this summer, for his leadership qualities and ability to inspire. Teammates talk of the dressing-room going quiet when Kompany opens his mouth.
A contract offer is on the table but remains unsigned for now while he reassures himself that he will play enough first-team football to commit to a 12th season here.
Now he appears to be clear of a succession of muscle injuries that threatened his career, Kompany wants to stay part of the set-up at City but has no wish to finish his career with their sister clubs in New York or Melbourne.
And what a way to prove it, thundering in the goal that keeps City ahead of Liverpool in an enthralling title race.
In theory it could be Kompany's last game at the Etihad as a City player apart from his testimonial.
The fact that game is scheduled for September indicates that he has no intention of leaving.
After his latest act of heroism, it's unlikely the fans would let him leave anyway.