Saudi Arabia sprang one of the biggest World Cup shocks of all-time, and Lionel Messi couldn't believe it.
The Saudis, roared on by a passionate fanbase in Qatar, incredibly came from a goal down to beat Argentina 2-1 and set the 2022 World Cup alive.
Messi had opened the scoring with a penalty in the 10th minute, and then had a goal disallowed in the first half as teammate Lautaro Martinez had two.
Herve Renard's underdogs then came back with two goals at the start of the second period though, with first Saleh Al Shehri finishing well and then Salem Al Dawsari scoring a superb second.
Messi and Argentina tried to hit back but were denied, and one of the great World Cup stories was written.
Here's how Messi's day went.
1. At the heart of things
Right from the outset it was possible to see just what Messi's role in this Argentina World Cup bid will be.
Everything, basically.
The No.10 took up a central position for his side, switching between being the foremost attacker and the one dropping in with Lautaro Martinez, who could be about to have an excellent tournament with his captain's not inconsiderable help.
Every move was going through the skipper, and each one of those moves was made better with his input.
He should have scored with an early chance he rolled too close to goalkeeper Mohammed Al Owais, but that was only serving warning for what was coming later.
2. Saudi Arabia fans make their voices heard
Everyone loves Messi, right?
Well not the very loud and very proud Saudi Arabia fans, who jeered the Paris Saint-Germain man's every touch in the opening stages, also barracking him when he took a corner.
It is nothing he is not used to of course, as he's singled out by pretty much every opposition he faces, but it probably isn't the way he'd like to have started his last ever World Cup.
The brilliant Saudi fans were boisterous throughout the opening exchanges, but there was soon to be a moment that silenced even them.
3. Spot on, as expected
No-one, not a single person inside the giant Lusail Stadium - the venue where the final will be held - expected Messi to miss from the spot when he stepped up to take his penalty.
The No.10 notched in the 10th minute to get Argentina's campaign up and running in the smoothest possible manner, settling his teammates too as they battled to get the better of a determined, and often robust Saudi side.
It was only a penalty, okay, but there are ways to take them, and although they looked vastly different there was a similar sort of authority to the kick that we saw from Gareth Bale in Wales' draw with the USA late on Monday evening.
He was just never going to miss this.
4. Where do you draw the line?
As mentioned above, Martinez will surely score goals for Argentina in this tournament, but he'll need to stay onside to score them.
His skipper also had a goal ruled out in the first half, and the South Americans were soon made to pay for mistiming their runs - only slightly in one case - as Saudi Arabia roared back into the match with those two stunning strikes at the start of the second period.
The Lusail Stadium seemed to lift off when first Saleh Al Shehri clinically, and then Salem Al Dawsari brilliantly turned things around for the underdogs.
Messi could only watch on, and as his teammates seemed to crumble he looked lost.
5. How on earth did that happen?
It was truly remarkable, and one of the great stories of any World Cup.
Saudi Arabia's comeback to from a goal down at half-time to lead within eight minutes of the restart of the second half was quite unlike anything we've seen in a long time.
But we still expected Messi and Argentina to respond.
He tried, and there were a couple of delightful passes, but but in truth the spirit of both himself and his team looked broken by the team he skied a free-kick over the bar to the delight of Saudi fans.
Then came a header that was comfortably saved, and the impossible became a reality.
This is a result to shock the world.
