But while the Welshman’s soon to be confirmed win will have come as a surprise to many, it doesn’t shock Brailsford – after all, Thomas’ entire season has been planned around the race.
Thomas went in to the race as Team Sky’s other ‘protected rider’ and the man renowned for being the ultimate domestique will complete his win in Paris on Sunday.
“In December we decided his season should be based around peaking in July. He did it perfectly,” said Brailsford.
“It couldn’t have climaxed in a more emotional way. It seemed like such a long race and on a knife edge for the last few days and then all the emotion came out.”
The 32-year-old took control of the race by winning two stages in the Alps in the second week of the three-week race – taking the leader’s yellow jersey after winning Stage 11 and refusing to let go of it.
On the following day’s Stage 12 he won again, becoming the first Briton to claim victory on the fabled Alpe d’Huez.
Thomas was equal to numerous challenges from second-place Tom Dumoulin in the Pyrenees in the final week, while defending champion Chris Froome faltered.
In a penultimate stage time trial on Saturday that world champion Dumoulin would have been looking at as a way to eat into Thomas’ advantage and add the Tour to his 2017 Giro d’Italia title, the Dutchman was left to feed on scraps, making up only 14 seconds to Thomas.
Tour convention dictates the yellow jersey is not challenged on the final, processional, stage in Paris, so Thomas knows he only has to cross the finish line to become the third Briton to win the race – after Sir Bradley Wiggins in 2012 and Froome’s subsequent quartet of wins.
Like his compatriots before him, success for Thomas at the Criterium du Dauphine – an excellent indicator of form heading into the Tour – proved a good omen.
Wiggins won the week-long race in 2012 before going on to triumph in the Tour and Froome has won the Dauphine on three occasions, each time then going on to add the Tour title.
“Psychologically he went into the Tour with great self-confidence and a quiet assuredness and he just quietly went about his business, chipped off every day and then found himself in the yellow jersey,” added Brailsford.
While Froome will have gone in looking for a fourth successive Tour title and become holder of all three Grand Tour titles – he won 2017’s Vuelta a Espana and the Giro in May – Brailsford says the 33-year-old deserves huge credit for assisting Thomas.
He was widely expected to join Belgian Eddy Merckx, Spaniard Miguel Indurain and Frenchmen Jacques Anquetil and Bernard Hinault on five wins.
But his hopes of also matching Merckx’s record of four consecutive Grand Tour victories were ended in the Pyrenees in the final week.
Brailsford added: “The person who deserves a mention is Chris. We had two leaders – Chris was the actual leader, Geraint the protected second leader.
“And the moment it dawned on him that he wasn’t going to win, Chris immediately switched to the support of Geraint.
“All the focus was on Chris and that let Geraint just get on with his business and when the pressure did come he had Chris at his side, and he supported him with such grace that it gave him a calmness that helped him through.”
Alexander Kristoff ensured UAE Team Emirates ended their Tour de France on a high, as he won the iconic final stage – the famous sprint finish on the Champs-Élysées.
The Norwegian had yet to record a stage victory at this year’s Tour, narrowly missing out earlier in the race, but on Sunday he was on top form, timing his final sprint to perfection.
Kristoff edged out home favourite Arnaud Demare in the final sprint, getting his wheel across the finish line ahead of the Frenchman in a finale that was a display of the reigning European champion’s power.
“I’ve dreamt about this victory for many years,” Kristoff said.
“I’ve been close before but I’ve never managed to beat the faster guys like Greipel, Kittel and Cavendish.
“But today they were not here – they are out after the mountains. So today I was the fastest and I am super happy.
“It’s a dream come true.”
Meanwhile, Kristoff’s team-mate Dan Martin finished eighth in the general classification standings, nine minutes and five seconds behind winner Geraint Thomas of Team Sky, and also picked up the award for the most combative rider of the tour – his first award as a UAE Team Emirates rider.
“This is an amazing moment,” Martin said.
“What a magical place to be, with the Arc du Triumph in the background and the Champs Elysees in front of us. It’s all just starting to sink in now.
“It’s always special finishing the Tour, but even more so today.
“I have really enjoying this year’s race and I’m a bit gutted it’s over. So now I am just looking forward to next year even more.”
Martin crashed earlier in the Tour, which ruled him out of contention for the podium finish that he was targeting.
Thomas will become the third British winner of the race, joining Sir Bradley Wiggins and Chris Froome, with the trio winning six of the last seven editions, all in Team Sky colours.
His closest rival at the start of the day, Tom Dumoulin, won the stage by one second from Chris Froome, but with Thomas only 14 seconds back the Welshman had more than enough in hand.
Thomas will carry a lead of one minute and 51 seconds into Sunday’s traditional procession into Paris before the sprinters fight it out for glory on the Champs-Elysees.
Thomas was embraced by his wife Sara and Team Sky principal Sir Dave Brailsford at the finish, and appeared to wipe away a tear.
“I can’t believe it,” he said.
Froome, who came here looking for a record-equalling fifth Tour title and seeking a rare Giro-Tour double, had to settle for third place, taking back the final podium spot from LottoNL-Jumbo’s Primoz Roglic with his second place on the day.
There was brief confusion when the timing splits appeared to show Froome had beaten Dumoulin by one second to take the stage, though it was soon corrected.
“That’s crazy,” Dumoulin said. “I didn’t know anything about split times and I still thought Froome was one second ahead of me when I crossed the line. Wow.”
Thomas emulates Wiggins in converting himself from an Olympic team pursuit champion into the winner of the world’s biggest road race.
The 32-year-old had never before finished in the top 10 of a Grand Tour, though, in his only previous serious attempt to win one, he was forced to withdraw following a crash midway through last year’s Giro d’Italia.
Intermittent rain, the first significant downfall of the entire Tour, created unpredictable conditions on Saturday’s 31km course.
There was one significant scare for Thomas with around 19km to go when the bike almost slipped from underneath him on a right-hand bend.
Thomas may have known he had a buffer to play with, but he was not taking it easy as he was fastest through the first and second splits before grinding up the Col de Pinodieta and dropping back.
Dumoulin had to console himself with his third career Tour stage win – all of which have come in individual time trials.
The Team Sunweb rider’s day did not get off to an ideal start when he could not find his time trial skinsuit in the morning.
But with his clothing sponsor based just across the Spanish border in San Sebastian, an emergency call was placed and they whipped him up a new set of the world champion’s rainbow stripes in time.
Irishman Dan Martin shipped more than two minutes in the time trial, but the UAE Team Emirates rider – named the most combative in the Tour overall – did enough to protect his top 10 place as he is set to finish eighth overall.