It all happened so fast you weren't sure if it had happened at all. Not then, not an hour later, not the morning after, not two days on and not that it stopped them. "You can see it clearly on the television," said Gonzalo Higuaín, but you couldn't. For some time, you couldn't see it on television at all, let alone clearly. The only thing you could be sure of was that you weren't sure at all. And yet they'd never been so sure of anything in their lives. So it was that what started as a soldier against mercenaries inevitably ended in an ugly war. And the trenches were dug in familiar territory.

Confused? You're not the only one. So, let's set the scene. It's the biggest game of the season so far. Saturday night: third versus first. Real Madrid travel to Valencia, where the Chés have come to hate the team from the capital – hostile bids, confrontations, controversy and competition, plus a little politics, turning this into the rivalry Mestalla feels most. Real Madrid have won 10 games in a row, scoring 39 league goals in only 11 games, but the fixture list has been kind. Here at last is a proper test: the first game where they may not be favourites, theoretically the hardest trip after the Camp Nou. It's one of those games – and there are fewer and fewer of them – where you can't help getting a little giddy. Genuinely excited.

On the morning of the game, the Valencian newspaper Super Deporte leads with a photograph of Cristiano Ronaldo and Roberto Soldado – whose name conveniently translates as Robert Soldier. The headline shouts: "Soldiers against mercenaries." Because Soldado doesn't get paid and mercenaries aren't soldiers. On Super Deporte's website, a target is placed on Ronaldo's head. El País calls it "legends against giants" and the club encourages fans to carry the seynera – the flag of the Valencian community. Meanwhile, Unai Emery, whose team had Barcelona on the ropes and drew 2-2 with them at Mestalla, is trying to come up with another strategy; so too is José Mourinho.

A swiftly taken free-kick (too quick for the cameras) and a smooth strike from Karim Benzema give Madrid a lead. At half-time, Madrid are comfortable. In the second half, not for the first time, they slip: less intense, less aggressive, less advanced. But Sergio Ramos scores a header with 19 minutes to go and it's all over. Only it's not: it is instead the first of four goals in11 minutes. Soldado makes it 2-1. Valencia are getting on top – Madrid's possession slips to 34% in the second half, their shots dry up – and the game gets edgy. Ten players get yellow cards – and Pepe and Lassana Diarra aren't among them. Mourinho and Jordi Alba are gesturing and shouting at each other. The defender, Mourinho seems to say, is a "clown".

Soldado's goal gives hope but it is torn away three minutes later. A Valencia corner, a big hoof, goalkeeper Diego Alves dashes out to head it away but misses it, Ronaldo goes past him and scores from a tight angle. 3-1. Mourinho sprints down the touchline and leaps on to the back of substitute José María Callejón. "The winning horse," declares Marca the next day, but the horse still has to make it to the finishing post and there are more goals to come and hope is restored. Soldado gets another. 2-3. And there are eight minutes left, plus stoppage time.

Then it happens. The last attack arrives just as the clock prepares to strikes midnight. A Tino Costa free-kick on the left, practically a corner. Time for a Hail Mary. Alves is up there, hoping that he won't miss the header this time. Artiz Aduriz leaps, Higuaín gets in front of him, between them they make contact and tumble to the floor. Iker Casillas flies fast, unbelievably fast, the ball smashes against the bar – if the goalkeeper has saved it, which at first it looks like he has, it's an astonishing save. It drops to Soldado, who nudges it goalwards. There's a crowd. Higuaín, on the turf, a few yards out, shifts to his right, and blocks it. It's one of those moments when the commentary consists largely of eh, ee, ooh, ah, wow, erm … and now Valencia's players are surrounding the referee! They are too, screeching at Teixeira Vitienes II – yes, there is a Teixeira Vitienes I – to give a penalty. Instead, he gives a corner.

"I'm sorry," says Higuaín afterwards, "but it hit me in the chest. I stopped it with my ribs and when it hits your ribs it is not handball, is it?"

No. But then he would say that. And some doubt that it did hit his ribs. At home, everyone is waiting for the replay. When it comes, it seems to show that Casillas may not have saved it. It also seems to show the ball hitting Higuaín in the chest. Sport calls it a "Robbery at Mestalla", El Mundo Deportivo talks of "favours to Madrid". The following morning, the Madrid papers barely mention it, preferring to focus on what it means for the title race. "It's games like these that win you leagues," Marca says; AS leads on "that's how you win leagues". Casillas calls it the kind of match "you look back on as significant". They have a point, too. Madrid now have 11 wins in a row and there is a solidity, intensity, variety and voracity about them that makes them look increasingly like favourites for the title.

As the papers are sent, another camera angle appears – this time from La Sexta's pitch-side ENG (Electronic News Gathering) cameraman, whose footage doesn't automatically get fed into the coverage of the game itself. And this time, from this angle, it looks like a clear handball. This time, it looks like a deliberate handball – like Higuaín reached out and slapped the ball wide. Valencia's director of communications, Damiá Vidagany, is furious: "huge penalty", he says on Twitter, "but it's not Ovrebo or Stark". He's talking robbery and conspiracy. "Higuaín lies, Casillas lies, La Sexta lies," he tweets. La Sexta is the channel that showed the game live in Spain. Vidagany tells Cope radio that La Sexta has refused to hand over the image that shows the clear handball and rails against the "disgraceful" coverage and the lack of objectivity of its commentators.

But Mediapro, the company that distributes the footage and handles the Sexta's coverage, does hand it over as normal. Valencia's website uses the footage to show that it was a penalty; so, on Monday morning, does the cover of Super Deporte. For some it is too late, but the new angle suggests that the penalty is clear. The trouble is that soon another, less clear angle emerges which again seems to suggest that it is Higuaín's chest that stops the ball, not his hand. The images are pored over, again and again. On election night – and one Catalan sports newspaper greets the results by declaring that the arrival in power of Mariano Rajoy means more help for Madrid – they're taking sides. On all channels. Politics and sport. Sometimes, both at once.

Those sides are familiar sides. And all the while, standing in the middle is a referee taking the flak – because of course it's his fault that a load of snarling players made the game ugly and he could not see a penalty without any replays that others could not see with them. Some things came very sharply into focus this weekend; the penalty was not one of them – even if they said it did.

And, boy, did they. Sport's cartoon shows a hand dropping a voting slip in the polling booth. "Of course," runs the caption, "in Madrid they reckon he put the vote in with his chest." A poll in AS shows that 58% think it is not a penalty; a poll on Super Deporte says 76% think it is. Their cover leads on the exhibits A, B, and C: photos as evidence. "Indignant!" says the cover. Sports screams "IT WAS A PENALTY!", El Mundo Deportivo calls it a "PENALTI CLARÍSIMO!", with one columnist noting that the referee "closed his eyes so as not to see what he did not want to see".

Oh calm down dear, responds AS, the paper that showed such admirable calm and restraint in reinventing the rules and inventing the ludicrous Villarato theory, which claimed that there is a refereeing conspiracy to aid Barcelona. Its editor started his column with a simple judgement that brokers no argument. "Stop making such an fuss: there was no handball," he says. Despite seeing the additional footage now, the paper's former referee was adamant that it was not a penalty. Just as adamant as the Barcelona and Valencia dailies' experts were that it was. And as for Marca's refereeing expert, a linesman famous for getting it wrong, he says "clearly there wasn't a penalty".

Clearly.

Disclosure: La Sexta is the channel this column works with (but was not commentating on Saturday).

Talking points

• Granada's game should have been wonderful. Last week, Carlos Martins learnt that his little son is seriously ill and needs a bone marrow transplant. His team-mates, both club and country, have rallied round him, donation points were set up round the ground, team-mates have promised to donate, and there were banners in support. And then he only went and scored a beauty to give his struggling side a 2-1 lead. When he celebrated the goal gripping the T-shirt his team-mates had worn in his support, he began to cry and there was a colossal ovation. It was the perfect night; a genuinely touching moment. And then someone threw an umbrella from the stands which hit the assistant referee in the face, drawing blood. Two minutes after Martins' moment, the game was abandoned.

Afterwards, the Granada president Quique Pena was busy trying to deny any blame, noting that the person who threw the umbrella was not a season ticket holder, had been picked up by police, and was armed with an umbrella – on a night when it was raining. Fair enough, you may think, even if it did lack a little grace in its urgency to protest the club's innocence. What was a little less fair enough was his insistence on repeatedly noting that the person who did it was Moroccan, like that makes all the difference.

• Athletic Bilbao beat Sevilla this weekend to make it 11 games unbeaten and also to make a little piece of history: Joan Ramalho became the first black player ever to turn out for the club.

• José Antonio Reyes played a key role for Atlético Madrid and ended up with the fans chanting his name. "That makes me the happiest man in the world," he said. But he shouldn't get too used to it – doing so was largely a way of slagging off the coach Gregorio Manzano and it's not so long ago that Atlético fans' preferred chant was "Reyes, die now!"

• Barcelona's home aggregate score is now 30-0.

Results: Villarreal 1-0 Betis, Barcelona 4-0 Zaragoza, Valencia 2-3 Real Madrid, Real Sociedad 0-0 Espanyol, Sporting 2-1 Getafe, Osasuna 0-0 Rayo, Sevilla 1-2 Athletic, Atlético 3-2 Levante, Granada-Mallorca 2-1, but abandoned after 60 minutes.

Monday night: Racing-Malaga.

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