THERE were 30,000 inside Celtic Park and not a single supporter around the country who failed to see the significance of this result.
Aberdeen dissolved Celtic's unbeaten and clean sheet sequences. They finished their hopes of the double. They effectively sent them into hibernation until the summer's Champions League qualifiers. But it was not about Celtic on the pitch and nor was it about the consequences for their season.
Aberdeen made themselves the story. Two electrifying results over the past nine days have given them the most impressive, convincing look they have had for 20 years.
Powering their way to the League Cup final last weekend sent the north-east aflutter; it felt as if there was a trophy with their name on it. After a week of thinking about that, their horizons broadened even further. Dumping Celtic out of the Scottish Cup was like removing a massive obelisk overshadowing everyone else in the tournament. Instantly it was wide open and Aberdeen supplanted the holders as the new favourites. A club which has won nothing for over 18 years has muscled its way to the front of the pack. Aberdeen is daring to believe it might lift both cups within eight weeks.
Not since Hearts in 2005/06 has there been a team from outside Glasgow with such a persuasive mix of attitude and ability. Celtic were not caught cold or surprised by Aberdeen - Neil Lennon had been impressed when he saw them rout St Johnstone and his players were adequately warned - but they met a team that was a match for them. Barry Robson and Willo Flood came back to Celtic Park and simply bossed the midfield.
They were a pair of terriers, streetwise and hard as nails, constantly breaking up Celtic moves and turning over possession. Then they would release Peter Pawlett, Jonny Hayes, Niall McGinn and Adam Rooney and their pace and strength put Celtic on the back foot.
Emilio Izaguirre and Adam Matthews cannot bomb on when they have to worry about wide players with the speed and technique to hurt them on counter attacks. Pawlett has blossomed into arguably the most exciting young player in the country. As he did in the semi-final, he burst from midfield to score with a low, angled shot.
Aberdeen supporters are not used to their team holding its nerve. To do so twice in a week is unprecedented in recent times. It is obvious that confidence and calm is spread around the side by the senior players. Robson, Flood and McGinn know the pressures of playing for Celtic. Russell Anderson has seen it all.
Aberdeen did not start well and were a goal down within eight minutes. For the only time in the game Georgios Samaras had space in midfield and he struck a lovely ball over the top which Anthony Stokes brilliantly controlled before burying a finish. It did not shake Aberdeen.
They rattled Celtic from one corner and then scored their equaliser, through Anderson, from another. Pawlett scored and then hit the post. Virgil van Dijk should have equalised with a header, but Rooney had a late one-on-one chance which could have made the win more emphatic.
Their fans have been singing "the sheep are on fire" about all of this over recent months. The manager Derek McInnes has been almost pathologically committed to keeping a lid on expectations, and no wonder. Aberdeen have let their supporters down so many times staff at the Samaritans have been on overtime since 1995. The wait is not over yet.
"We can't get carried away," said Robson. "We have won against a terrific team, who I have a lot of respect for, in a great stadium to get into the next round. We came down and played the way we wanted to, so let's go and see where we can move on to. We know we have a good side and that we can hurt teams.
"A lot of teams crumble here after suffering an early setback. You are playing against top players at Celtic Park and they can sense a bit of fear in you. But after about 20 minutes, we came out and showed that, after going a goal down we could start playing. That shows confidence and that's how you win games.
"We need to be honest: the hardest part of the season is still to come. I've been there, I've done it and I've seen it. We enjoy it for about half an hour maybe, then start thinking about St Mirren next weekend. Let's see if this can be a trophy winning team.
"Let's see how far we can take it. Let's see if we've got the mentality, strength and desire. This will mean absolutely nothing if we don't go on to win the cup."
Robson was the beating heart of Aberdeen's performance. At 35, has he got another season in him after this one? "I feel like I'm 25," he said. "Seriously. I still feel good. I've looked after myself so hopefully I can keep going. I'll see where this season takes me, then maybe I can go another year or even two after that. I haven't had time to speak to the manager about a contract yet, we've had too many games."
That is an occupational hazard for a team capable of going the distance.