Ronaldo’s 88th minute strike, a trademark effort from the edge of the area, crowned a quite magnificent match in Group B which has set the 2018 tournament alight.
All the ingredients were there in advance, of course, following Spain’s traumatic week in which they had sacked one manager, appointed another and split the nation with the way it was all done.
It was also an Iberian derby between two genuine contenders for the title, it was Ronaldo against Iniesta in possibly their last World Cups, it was the biggest game of the group stages.
But even taking all that into account the tie over-delivered with an enthralling spectacle full of drama, controversy, goals, and emotion.
For Spain, the final result will seem tough in the short term because they showed remarkable courage and fortitude to come from 1-0 and 2-1 down to lead 3-2 through two Diego Costa goals and a quite spectacular effort from Real defender Nacho.
But perhaps in the longer term they will reflect the performance and the mentality on show was more than enough to ensure they World Cup is not going to be derailed by the events of the last
Spain, of course, went into the match under the leadership of a new manager — the ex-Real Madrid and Bolton defender Fernando Hierro, who had been asked to step up from the role of director of football to lead the team following the sacking of Julen Lopetegui.
Lopetegui was unceremoniously axed by the Spanish Football Federation for going behind their backs to engineer and announce a move to Real Madrid, where he was unveiled in tears on Thursday having already been stripped of his role as head coach of the national team.
The depth of the crisis cannot be underestimated, especially for Spanish Football president Luis Rubiales who has split opinion in Spain with his decision and earned bitter criticism, as you might expect, from Real Madrid President Florentino Perez.
Rubiales took his place in the stands at the Fisht Stadium in Sochi, nevertheless, for a match that he knew could impact on his future, on Hierro’s future, and on the unity of not just a team but a nation.
Unfortunately for him it took just three minutes for the crisis to deepen, at least temporarily.
Ronaldo, a Real Madrid man of course who will have Lopetegui as his club manager next season should he stay at the club, embarked on his first run down the left wing, produced a trademark step-over and tempted the careless and rather naive Nacho into a stupid challenge.
Yes, you could argue that Ronaldo left his leg in to be hit and, yes, Nacho tried to look as though he was pulling out. But the right-back caught him all the same and referee Gianluca Rochhi had no real choice but to award a penalty.
There was never any doubt over who would take it or whether he would score, and Ronaldo duly struck a perfect spot-kick past David De Gea for 1-0.
It was exactly the start embattled Spain didn’t need and it was also an historic moment Portugal’s irrepressible legend.
Ronaldo is now the first player in history to score in eight consecutive major tournaments (including four consecutive World Cups) and his dream of adding a Jules Rimet trophy to his European Championship suddenly looks possible.
Spain were clearly rattled but they continued to play their triangles, with David Silva creating two decent chances, and found their way back into a terrific match with two goals from Costa.
The first included everything that you either love or hate about the former Chelsea man. First, he battered Pepe with a brutal aerial challenge and then, having got away with it, scored a stunning individual goal as he twisted one way and then the next before driving the ball home from 20 metres.
With their tails up, and Hierro increasingly animated, the 2010 world champions almost went 2-1 up when Isco hit a thumping long-distance drive that cannoned back off the crossbar and landed plump on the goalline with keeper Rui Patricio well beaten.
But their wavering concentration was punished again on the stroke of half time when the ball the ball fell to Ronaldo on the edge of the area and struck a speculative left-foot shot straight at David de Gea. It was an easy ball to stop but the Manchester United goalkeeper, with one knee on the floor, just fumbled it into his own net.
Thankfully for De Gea there was far more drama ahead, including a goal from Costa in the 55th minute when he made sure he reached a Sergio Busquets header first to score from close range.
It was 3-2 three minutes later when Nacho hit a quite remarkable swerving shot from long distance with the outside of his right foot which arrowed into the net at high speed – and it seemed Hierro was set for the most memorable debut.
That would have been the case had it not been for Ronaldo, who showed his own unwavering mentality when he clipped home that late free-kick to complete a heady and dramatic night.
The end result will probably see both sides go through to the knockout stages given that Iran and Morocco are the other teams in Group B. But for now we should just enjoy and wallow in the spectacle.
Patricio 6; Cedric 7, Pepe 7, Fonte 6, Guerreiro 6; Fernandes 6 (Mario 68; 6), Carvalho 7, B Silva 6 (Quaresma 69;), Moutinho 7, Ronaldo 9; Guedes 7 (A Silva 80; 6).
De Gea 4; Nacho 6, Pique 6, Ramos 7; Coke 6, Busquets 7; D Silva 7 (Vaxquez 86; 6), Isco 7, Iniesta 7 (Alcantara 70; 6); Costa 8 (Aspas 77; 6).
Gianluca Rocchi (Italy)