That a big match was on at Mohammad bin Zayed Stadium was in no doubt an hour before the start.
That much could be seen in the quick-stepping, almost bopping, of fans making their way through to this slick, polished and proud stadium.
Everywhere was littered huddles of fans; you will not be surprised to know that the vast bulk were from Al Ain, purple scarves draped casually about them.
Near the main entrance two men stood selling flags. "Al Ain flags only," one insisted when asked, tersely tut-tutting even the notion that they could be in possession of Al Jazira flags.
As ever, the place to be at an Al Ain game is with the Al Ain fans. Except that there was no place, and barely even standing room, in the West Stand.
Their supporters would still be scurrying around at the end of the first half, frantically looking for someplace to sit.
They were well into it before the game began, drowning out even the music on the PA system with their own songs.
The first sounded like that old favourite, the not particularly inventive ditty of football fans around the world, imported from Spain, "Ohhhhle … ole, ole, ole!" except that it could so easily be mistaken for "Alll Ain … Al Ain, Al Ain, Al Ain!" In the North Stand, Jazira's band and fans, outnumbered, gave honest competition.
In the stands was where the action was for 45 minutes; the first half was a tense, taut one, squeezed and condensed through the middle of the pitch.
Both teams played last night precisely as if they knew that this was a vital, possibly season-shaping, top-of-the-table clash - the one that Jazira coach Franky Vercauteren had been so keen to play down, pre-game.
Little errors of judgement blighted the half, though the biggest was the goalkeeping gaffe from Khalid Essa which gifted Asamoah Gyan with Al Ain's opener four minutes in; Essa's attempted clearance, after he loitered far too long, rebounded off Gyan's extended foot and into an open net.
A number of occupants of the West Stand didn't realise what had happened. Once they did, they broke into a song sung to the beat of We Will Rock You, chanted with as much gusto and glee as Queen - or any group of fans - could ever have done the original. When Essa walked to take his place in goal at the start of the second half, in front of the purple sprawl of Al Ain fans, he did so with a wry smile in response to a volley of good-natured joshing from the fans.
At half time came a message of goodwill for Sheikh Khalifa, the President of the UAE, from a relay running team of 71 runners, 40 of them professionals, that had begun its race from the Burj Khalifa. Perhaps they also sent a message to the two sides to put on a show worthy of a clash between the champions and pretenders, because the game expanded - as if suddenly filled with positive energy. Now the pitch seemed bigger, there was urgency in idea and action. Jazira had at least pressed for much of the first half and they were rewarded with an equaliser soon after the break, the kind of simple goal from a corner that is bound to drive coaches crazy.
That it came from the head of Juma Abdullah, a former Al Ain player, probably drove more than just the coaches crazy. But as they had done at Baniyas a few weeks ago on conceding a goal, Al Ain's fans simply brought more noise into the stadium.
Officially, there were 21,455 fans at the ground and even if we allow for a little exaggeration, the noise generated by Al Ain felt as much, if not more.
And visibly, Jazira and their fans wilted in front of this imposing wall of sound. Just over 10 minutes after the equaliser, Fawzi Fayez's deflected shot, off the Jazira defender Lucas Neill, secured a lead and there was enough delirium to feel as if the stands were shifting.
Jazira willed themselves on and had chances, but it was desperate stuff. What looked like a serious injury to Al Ain's keeper, Walid Salem, failed to dampen his fans, and the extra minutes added after Salem regained his feet allowed Gyan to punctuate the game with an exclamation deep into added time.
Al Ain's players stayed on after the final whistle, walking over to the West Stand to acknowledge their fans, and it looked a special bond.
They did a little jig, celebrating as if the title had already been won. Big games have a way of doing that.