George Russell, Britain's newest Formula One recruit, revealed his mother swore and his father was left on the brink of tears when he told them he had been hired by Williams.
The 20-year-old from King's Lynn, Norfolk, will join Lewis Hamilton and McLaren rookie Lando Norris as the third British driver on the grid next season after signing a multi-year contract.
The highly-rated Russell, already on the books at Mercedes and on the verge of winning the feeder championship to F1, Formula Two, learned of the news during a 20-minute meeting with Claire Williams, deputy team principal for the British constructor, at last month's Russian Grand Prix.
"I had a message from Claire to go and see her after qualifying," Russell told Press Association Sport.
"I was hoping for the best but I wasn't sure. Then she said 'we want you for next year', and I said 'absolutely'."
From the Williams' motorhome, Russell dashed along the Sochi paddock to tell his parents, Steve and Alison, who have been with their son for every step of his formative motor racing career.
"They were both absolutely over the moon," he added. "I think my mother's exact words were, 'oh f****** hell'.
"My father had a tear in his eye and said he had been waiting for this day for 20 years. It then hit home what a massive deal it was."
Russell, who becomes the first Briton to drive for Williams since 2009 world champion Jenson Button began his career there at the turn of the century, addressed the team's staff alongside Williams at their headquarters in Grove, Oxfordshire on Friday.
The team's announcement comes a little more than a month after McLaren confirmed they will be promoting Norris, 18, next year, and thus signalling the potential start of another golden age for British motor racing.
Russell was signed as a Mercedes junior in 2017 and was promised an F1 seat by team principal Toto Wolff if he won the F2 championship this year.
He holds an almost unassailable 37-point lead ahead of next month's season finale in Abu Dhabi following an impressive debut campaign in which he has won six races.
In his role as Mercedes' reserve driver this year, Russell has also benefited from watching Hamilton at close quarters as he edges towards his fifth world championship.
"I have been in a very privileged position to be at arm's length to, in my opinion, the best driver ever in F1," Russell added.
"Lewis often gets portrayed as a guy that is not overly-committed, that is occupied with his other activities and not fully focused on Formula One.
"But when he arrives at the track, the amount of effort and work he puts in with his engineers, getting the team fully motivated, and leading them in the right direction, is truly incredible. I have learned a huge amount from him and understand that you cannot rely purely on natural talent."
Russell will be handed the unenviable task of leading Williams out of the doldrums. The famous British team have enjoyed a glorious past, winning a combined 16 drivers' and constructors' championships, but they are rooted to the foot of the standings with just seven points after a miserable season.
"I have no concerns about that," Russell said. "If I want to be the best driver in F1, or emulate the likes of Lewis, then I have got to be not only quick, but I have got to lead the team, too."
Russell will replace Lance Stroll, who is bound for Force India next year after his fashion billionaire father Lawrence's takeover of the team.