Simon Yates stepped from his team bus in Escaldes-Engordany on Saturday lunchtime, before the penultimate and decisive stage of the Vuelta a España, greeted his girlfriend and then gave the answers he has been giving for the nine days he has had the leader’s red jersey.

He was as understated as always, saying that he was focused only on the stage at hand, that his team had prepared for all possible scenarios, and that he would not start thinking of victory in Madrid on Sunday until the summit of the Coll de la Gallina, after 97km and six climbs.

Three frenetic hours later, Yates crossed the line third, behind Enric Mas and Miguel Ángel López, having done enough to ensure himself of victory. It will also mean a British clean sweep of the three Grand Tours with different riders, after Chris Froome’s win at the Giro d’Italia and Geraint Thomas’s at the Tour de France. No country has ever achieved such a feat.

“This morning was the first day I was really, really nervous,” said Yates at the finish. “We knew it was going to be a crazy day. You don’t know what’s going to happen, how the legs will respond, but thankfully the legs were good and the team were unbelievable, even the big guys were there and Adam [Yates’s twin brother] did an amazing job in the final.”

Before the stage Yates had neglected to mention his nerves or the fact that at 5am there had been a commotion outside his hotel that had woken many of the riders and staff on his Australian team. The real disruptors, he knew, would be Movistar and Astana, the two teams with the least to lose.

In the end Yates coped with the assault that came, initially, from Nairo Quintana, the Colombian winner of this race in 2016. Then it was the turn of another Colombian, López, known as “Superman” after an incident when he wrestled his stolen bike back from the thieves.

Adam Yates helped keep it under control, reeling López back in, and proved a strong ally to his twin brother. Adam went unnoticed for the first two weeks of the race – “I spent nine days chilling at the back,” he said two days ago – which was always the plan, keeping him for these final few days.

Quintana had tried. López had tried. The only thing left was for them to combine forces. As they disappeared up the road Yates could afford to stay calm and once again set his brother to the task of setting the pace. And then, as on Friday, he attacked, bridging to the Colombians and Enric Mas on the penultimate climb before, on the final incline to the summit, he let Mas and López go to fight it out for the stage.

Yates paid tribute to his brother’s “amazing” support, while Adam, on crossing the line, said: “We knew it was going to be a hard day. When it’s the last day there’s no holding back because there’s no tomorrow. Even if you blow it doesn’t matter. We controlled it as well as we could, but the last two climbs I was really hurting.

“The first thing I’ll say to [Simon] is thank him for attacking when he did because I was on my last legs.”

In Madrid on Sunday he and Mitchelton-Scott will celebrate their first ever Grand Tour win. “As a team we rode real well,” said Adam. “The strategy of holding me back and saving me for this last crucial week – it worked pretty well, didn’t it?”

Dave Brailsford, the Team Sky principal, toasted Yates’s victory but must have wondered at what might have been. Yates came through the British academy that Brailsford established but chose a different path when he turned professional – mainly, it seems, because while Team Sky were keen on signing him, they were not so keen on his brother. Mitchelton – or Orica as they were at the time – wanted both.

With the Yates twins enjoying success from the moment they turned professional, Brailsford expressed a strong desire to “bring them home” to Team Sky. But it has never looked like happening, not least because at the Australian team they have found themselves part of a project that has the express purpose of supporting them. Brailsford appears to have given up on signing either or both Yateses, focusing instead on tying up the young Colombian Egan Bernal on the longest and perhaps most lucrative contract in the sport’s history – five years and apparently worth £12m.

But the third Grand Tour of the season has been all about Simon Yates who, at 26, can look forward to many years of challenging for victory in Italy, France and Spain. The usual pathway would be from Vuelta to Giro or Tour. But the Yates twins have already proved – as Brailsford knows – that they follow their own path.