Nico Rosberg has announced his retirement from Formula One, just five days after winning his maiden drivers' championship.
The German secured the podium finish he required at the season-ending Abu Dhabi Grand Prix to beat team-mate Lewis Hamilton to the title by a mere five points.
Rosberg spoke in the aftermath about the stress he was under during a thrilling title race with the Briton, with whom he has endured a difficult relationship over their battle for supremacy in F1.
And the 31-year-old, speaking ahead of the FIA Prize Giving Gala in Vienna, confirmed his shock retirement with immediate effect.
"I want to take the opportunity to announce that I have decided to end my Formula One career in this moment here," said Rosberg.
"It's hard to explain, it has been ever since I started when I was six years old, I had a very clear dream and that was to become Formula One world champion.
"Now I've achieved that, I've put everything into it for 25 years of racing and with the help of everybody around me, with the help of fans and the help of my team and my family and friends I have managed to achieve that this year.
"So it has been an incredible experience for me that I will remember forever.
"At the same time, it has been very, very tough also because the last two years losing to Lewis were extremely difficult moments for me, which fuelled my motivation in a way that I didn't even know was possible to fight back and to achieve my dream finally."
Rosberg competed in 206 grands prix during his F1 career, winning 23 races and placing on the podium on 57 occasions.
The German made his debut for Williams in 2006 and stayed there for four years, before making the switch to Mercedes in 2010.
Rosberg finished runner-up to Hamilton in the 2014 and 2015 drivers' standings as Mercedes dominated F1, before finally getting the better of his rival this season.
In a statement on his official Facebook page, Rosberg added: "When I won the race in Suzuka, from the moment when the destiny of the title was in my own hands, the big pressure started and I began to think about ending my racing career if I became World Champion.
"On Sunday morning in Abu Dhabi, I knew that it could be my last race and that feeling cleared my head before the start.
"I wanted to enjoy every part of the experience, knowing it might be the last time... and then the lights went out and I had the most intense 55 laps of my life.
"I took my decision on Monday evening. After reflecting for a day, the first people I told were [wife] Vivian and Georg [Nolte, from Nico's management team], followed by [Mercedes team boss] Toto [Wolff].
"The only thing that makes this decision in any way difficult for me is because I am putting my racing family into a tough situation.
"But Toto understood. He knew straight away that I was completely convinced and that reassured me. My proudest achievement in racing will always be to have won the world championship with this incredible team of people, the Silver Arrows.
"Now, I'm just here to enjoy the moment. There is time to savour the next weeks, to reflect on the season and to enjoy every experience that comes my way. After that, I will turn the next corner in my life and see what it has in store for me..."