At 2-0 down Arsenal needed a hero, but no one predicted it would be Reiss Nelson.
The last time the winger played for the Gunners was November and he hadn’t scored a Premier League goal since October.
But he came off the bench here to be Arsenal’s saviour against Bournemouth, scoring a last-minute goal to complete an astonishing 3-2 comeback.
The scenes as the goal went in, and again at the full-time whistle moments later, emphasised the significance of it.
Mikel Arteta sprinted down the touchline to celebrate with his players after Nelson smashed the ball into the net when Bournemouth had failed to clear a corner. He was not alone too. Staff and substitutes charged on the pitch as well, hugging everyone they could get their hands on.
It was a similar story in the stands too as supporters lost control of their minds and limbs at a goal no one saw coming.
Seconds earlier Arsenal’s lead at the top of the Premier League had been three points, but with one swing of Nelson’s boot it was five.
How different the mood was to just 30 minutes earlier, when Arsenal had been staring down the barrel of a 2-0 defeat.
Bournemouth had taken the lead in just over nine seconds, with Philip Billing’s strike the second-fastest goal in Premier League history.
The Gunners were shell-shocked by it, caught out by a set-piece move from kick-off that was like something out of Ted Lasso.
It was sloppy from Arsenal and it was the same for the visitors’ second goal as Marcos Senesi lost his marker, Thomas Partey, from a corner to head home.
You could almost hear the cheers in Manchester at that point. City had won 2-0 earlier in the day against Newcastle to close the gap to two points.
No one expected Arsenal to slip up to Bournemouth, who are 19th in the table and have won twice away in the League all season.
Arsenal had to respond - and Partey did so five minutes after Senesi’s header. The midfielder bundled the ball home from a corner and suddenly there was belief again.
When Ben White scored his first Arsenal goal with 20 minutes to go, the comeback was well and truly on. Nelson created the goal, skipping past his man out wide and crossing for White to score.
The winger had only come on literally seconds earlier, replacing Emile Smith Rowe who had come on in the first-half for the injured Leandro Trossard.
It was a bizarre set of circumstances and one that summed up how luck can sometimes play a vital role in the hunt for a title.
Nelson wasn’t done there, though, and in the 97th-minute he scored a goal that could go down in history one day.
Arsenal swung in a corner, their 17th of the game, and Bournemouth could only clear it to the edge of the box. Nelson controlled the ball and then smashed it into the far corner with his weaker left foot.
From there, a noise erupted at Emirates Stadium unlike any that has been heard since it was opened in 2006. Time will tell, but it felt like a defining moment in the title race - and one nobody saw coming.
