Ronaldo, Messi; Messi, Ronaldo. First Messi responded to Ronaldo, then Ronaldo responded to Messi. You cannot keep these two down. If Real Madrid versus Barcelona is the greatest sporting rivalry on earth, it has come to be personified in two of the finest footballers there have been, men who define their clubs and this battle.
On a night that was billed as the match that would decide not just the league title but the Ballon d'Or, the deciding votes were put on hold for now. There will be more from these teams and from these two men. Between them Messi and Ronaldo have now scored exactly 100 club goals in 2012; between them they got all four goals here.
"I don't know if Ronaldo has done enough [to win the Ballon d'Or]," said José Mourinho. "All I know is that talking about who is the best player in the world should be banned because these two are so good."
The result maintains Barcelona's eight-point lead at the top of the table, although Messi and Ronaldo, with eight goals apiece, are level in goals plundered this season. They appear to break records every match. Ronaldo broke another one here, his 22nd-minute opener being the sixth successive clásico in which he had scored, the first to do so.
Xabi Alonso sprayed the ball to the right touchline, another long pass opening the pitch out, where Angel Di María and Mesut Ozil combined. The ball was worked across the face of the area, Sami Khedira found Karim Benzema and he held off his marker, turning to roll into the path of Ronaldo. His shot went in hard and low at the near post. He had now Ronaldo's celebration was the same as it was when his scored the league title-clinching winner here at the end of last season: Relax, I'm here. Another exhibit to support his case.
Ronaldo's problem, as so often, was Messi. The Argentinian scored the equaliser eight minutes later. Pedro's ball from the right ricocheted into the air. Pepe leapt but, under pressure and falling forward, was unable to make good contact with the header and the ball dropped on the edge of the six-yard box for Messi to nudge it past Iker Casillas. Now both men had got goals.
This had not been a great game until then. Barcelona had enjoyed more of the ball but failed to create clear chances and every time Madrid sprang, the pitch opened before them and the sense of danger was palpable. It was a familiar pattern for these games, except that this time Madrid's pressure did not start so high up the pitch. Instead they lay in wait, a little deeper. The best chances had fallen Madrid's way too.
Even before Ronaldo scored, Sergio Ramos headed a fraction wide from the visitors' first corner – Barcelona's weakness exposed again. Benzema had also scuffed a volley a long way wide and, almost immediately after Ronaldo's goal, the Frenchman hit a post, with Di María putting the rebound wide.
This time it was Messi's turn to lay down the challenge. A stunning free-kick from over 25 yards crashed past Casillas to make it 2-1. When Ronaldo, soon after, tried to score an overhead kick he missed it and the crowd laughed but not for long. A lovely ball from Ozil found him dashing in and he finished cleanly.
There was still life left in this game and, although Valdés blocked Gonzalo Higuaín's shot, it was Barcelona who sought the winner. With two minutes to go Martín Montoya hit the crossbar. Xavi's free kick then came back off the wall, Pedro's shot then went wide off the body of Alexis Sánchez and, in injury time, Andrés Iniesta released Pedro, who sprinted up the right, dashed inside and struck a shot fractionally wide.
A huge ovation rang round the Camp Nou and was immediately met with the final whistle. A goal for anyone else would not have seemed right somehow.