On Sunday evening Iñaki Williams boarded a plane north to Paris. About the time he set off from there to Le Havre on Monday, Nico Williams was heading in the other direction, south to Barajas and on to Las Rozas, 25km outside Madrid. On Saturday, a night none of them would ever forget – a delirious, joyous celebration of everything they are – they had embraced; then, for the first time, Bilbao’s brothers went separate ways. “It was always our dream to play together and see our mum happy,” Iñaki says. This week they won’t, a new chapter beginning in their lives. But they’ll be back and, boy, had they had a send off.

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As for their mum, Maria, she couldn’t be happier. The scheduling means hopefully she’ll be able to see both her sons take their next, giant steps, for a start. This Friday, Iñaki Williams will probably make his debut for Ghana against Brazil in France, aged 28. The following night, Nico Williams, eight years younger, will probably make his for Spain against Switzerland in Zaragoza. They arrive having celebrated those call-ups with a 3-2 win over Rayo Vallecano to take Athletic into a Champions League place. It was Inaki’s 239th consecutive game – yes, two hundred and thirty-ninth and, yes, consecutive – for Athletic. It was Nico’s 48th in total. It was also the first match in which they had both scored, San Mamés roaring all around them.

The first time Iñaki played for Athletic, back in 2014, he still didn’t know exactly how he had got there. He was 20 when his mum sat him down and told him how she was pregnant with him when she and her husband Felix left Ghana and crossed the Sahara by truck and barefoot – Felix still has problems walking – and climbed the fence into Melilla, Spanish north Africa. A few months later, Iñaki was born in Bilbao. Destiny, he calls it. “My friends and I talk about it: bloody hell, incredible. Everything happens for a reason. If I hadn’t been born in Bilbao, I could never have played for Athletic.”

Iñaki joined the club at 14, driven by an objective. In 2005 or 2006, with the family living in social housing in Pamplona and the financial crisis brewing, Felix left for London, desperately seeking work, doing everything and anything he could find. “I knew that if I made it, I would solve many things and that idea of bringing the family together again was the most important thing,” Iñaki recalled. “I dreamed of being a footballer but I also dreamed of uniting my family.” He did so at San Mamés: Inaki has played 346 times for the first team, deep into that consecutive run when Nico, who had come to the club aged 11, joined him.

Now for the first time they will play for different teams. If results go right, they could even face each other at the World Cup.

Nico was always a bit special, almost as quick as Iñaki but smaller, more skilful, more creative. “More talented,” by Iñaki’s own admission, even if he didn’t have the same drive, the same sense of destiny. He also had another advantage: he had his brother. Nico has only one tattoo, of a lion with its cub representing him and the brother who he says was like a father. When Felix left for London – “we saw him once a year for practically 10 years” – Nico was two or three. Iñaki would prepare his lunch, pick him up from school, take him to football, even referee games – the €10 fee came in handy. In short, raise him. He could be severe, strict at times, guiding him. Above all, there was love.

There was a glimpse of that at the Super Cup when Nico took off his runners-up medal; Iñaki admonished him and told him to put it back on again, to value what he had achieved. He also laid a gentle hand on Nico’s neck as he watched Real Madrid collect the trophy. After the semi-final when Nico scored his first goal, he had tweeted: “If I loved you any more I would die.” More messages came, like a proud parent following his son’s career. And when Nico found out about his Spain call-up this week, Iñaki saw a dream fulfilled for both of them.

Iñaki had played for Spain’s U21s and been called to the senior squad once before, in a friendly against Bosnia and Herzegovina in 2016, but never went back. He had been approached by Ghana, but turned down the opportunity, believing it was not his place: he speaks Twi but was born in Bilbao, feels Basque, and didn’t think it was right to take another player’s hope from them. The federation were insistent – they approached Nico too – and Iñaki changed his mind. Age played a part (at 28 this would probably be his last chance to go to a World Cup) and in the summer he visited Ghana for the first time in many years, seeing grandparents, family, places that shaped his life. There were long discussions, and something shifted inside him.

He talked about legacy, journey, lessons from his parents. “The moment has come to encounter my roots, and everything that Ghana and Africa means for me and my family, because Ghana has played a part in me being who I am as a son and a brother,” he said.

Even as they went their separate ways they were brought together, senior call ups unexpectedly coming at the same time, their likely debuts a day apart. If they do not play in Le Havre and Zaragoza respectively, they could begin their international careers on the same night: next Tuesday Spain play Portugal in Braga and Ghana face Nicaragua in Lorca. If Iñaki knew this was coming, Nico didn’t. Just 20, still living at home with his mum – the boss, as Iñaki calls her – this call wasn’t expected just yet, although he has been flying this season, flashes of something special, not least in his outrageous goal against Elche. Consistency too, he has played every game, starting five of the six.

“I’m not doing this to stop him going with Ghana; he’s young and a very interesting player,” Spain coach Luis Enrique said. “He’s playing more often with Athletic now. He’s progressing wonderfully. I like him enormously. We’ve had him in the junior squad and have been following him for a long time. I reckon the family will be delighted: imagine the party if they both go to the World Cup. And they reach the final, well, that would be the absolute business.”

As for the party, how about this? Nico’s call came on Friday; the following night, there was a celebration at San Mamés, the season’s best game so far. Athletic against Rayo, two sets of fans who sing together. Two managers who have shared so much, Ernesto Valverde and Andoni Iraola, facing each other for the first time. And two teams that really go at it: Iraola has likened his style to a kind of “organised chaos”, which as organisation goes is the best kind. The result was a wild, fun ride. “An ode to football,” “a monument to the game” one commentator called it.

“A fiesta with San Mamés as the disco, 44,000 singing along ... an explosive cocktail of football,” in AS’s words. “The perfect night,” Ander Herrera called it, ending with thunderclaps echoing round. “One of those nights that make you love football: pure rock and roll,” according to Athletic’s report. “You won’t enjoy a night quite like this for a while,” El Correo claimed.

In short, if you watched it: lucky you. If you didn’t: do. Even replayed it will reward, the kind of breathless, intense, unstoppable occasion that even the VAR couldn’t ruin – and, by God, it tried. It had 25 shots, five goals, including an outrageous outside-of-the-boot volley from Radamel Falcao, four disallowed, and two posts.

Osasuna 0-2 Getafe, Villarreal 1-1 Sevilla, Real Betis 2-1 Girona, Real Sociedad 2-1 Espanyol, Atlético Madrid 1-2 Real Madrid, Real Mallorca 1-0 Almería, Barcelona 3-0 Elche, Valencia 3-0 Celta Vigo, Athletic Bilbao 3-2 Rayo Vallecano, Real Valladolid 0-1 Cadíz

Above all, it had two brothers. “We enjoy them, they enjoy us,” Valverde said. The conditions were perfect and the Williamses tore it up, unleashing a hurricane. 0-1 down early, Iñaki scored a superb equaliser, his touch to tame Dani García’s pass and escape the defence impeccable. Oihan Sancet made it 2-1 with a gorgeously worked goal. And then came Nico’s strike, his brother running across and leaping into his arms, before Falcao’s absurd second half goal made it 3-2. Iñaki published a photo of that celebration declaring “to be continued …” but for now they must go their own way and things could not be better, the pitch-side interview with Iñaki beginning: “congratulations ... for everything.”

“We’re on a wave”, Williams senior said. “Saturday night, 9pm, two goals, a win. This is San Mamés and we’re grateful. We’re proud of being together, able to give Athletic nights like this. Our mum will be pleased with her boys.”