Days after achieving his lifetime ambition to win a Formula One world championship, Nico Rosberg has stunned the sport by announcing his retirement.

The Mercedes driver took to Facebook to explain his decision.

“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,” the German said.

A second at Abu Dhabi was enough to net Rosberg the Formula 1 title. Photo: Getty

“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.

“I took my decision on Monday evening.

“I’ve climbed my mountain, I am on the peak, so this feels right.

“My strongest emotion right now is deep gratitude to everybody who supported me to make that dream happen.”

The driver had given no previous indication of his intentions and had been at the team factory in Brackley on Thursday after a trip to his German birthplace of Wiesbaden.

Lewis Hamilton says he is not surprised that Mercedes teammate Rosberg is quitting Formula One after beating him for the world title.

“I’m probably one of the only people that it was not a surprise to,” Hamilton said.

“But that’s because I’ve known him for a long time. This is the first time he’s won (in their rivalry) in 18 years, hence why it was not a surprise that he decided to stop.”

The two have been competing against each other since their karting days and at Mercedes.

Hamilton won the 2014 and 2015 world titles before Rosberg turned the tide this year in an at times bitter rivalry between the former friends.

“But he’s also got a family to focus on, having children, and Formula One takes so much of your time,” Hamilton added.

“It’s going to be very very strange, and it will be sad not to have him in the team next year. The sport will miss him, and I wish him all the best.”

FAST FACTS ABOUT NICO ROSBERG

*Born: Wiesbaden, Germany on June 27, 1985 (31 years old)

*206 Grands Prix

Hamilton, right, says he’s not surprised by Rosberg’s retirement. Photo: Getty

*23 race wins, 57 podiums, 1 world championship

*Teams: Williams 2006-09, Mercedes 2010-16

*Rosberg is the son of Finland’s 1982 world champion Keke Rosberg, who won his title with Williams, and German mother Sina. He was born four days after Keke won the 1985 USA-East Grand Prix in Detroit.

*Rosberg grew up in Monaco and still lives there with his wife Vivian and daughter Alaia. He speaks five languages but not Finnish.

*He and Mercedes teammate Lewis Hamilton, a triple world champion, were teammates in go-karts in 2000. Rosberg tested for Williams in 2004, aged 17 and before he had his drivers licence. He declined a place to study aeronautical engineering at London University’s Imperial College.

*Rosberg made his Formula One race debut with Williams in Bahrain in 2006, alongside Australian teammate Mark Webber, scoring points with seventh place and setting the fastest lap. He ended 2006 in 17th place overall.

Rosberg and Hamilton get up close and personal. Photo: Getty

*In 2007 he was ninth overall. The following year he stood on the podium for the first time, a third place in Australia, but ended up 13th at the end of the season. In 2009, his last year with Williams, he finished seventh overall.

*Rosberg joined Mercedes – who had bought champions Brawn GP – for the 2010 season and partnered seven-times world champion Michael Schumacher. The younger German scored 142 points to Schumacher’s 72.

*Rosberg also outscored Schumacher in the following two seasons, taking his first pole and grand prix victory in China in 2012. In 2013, Lewis Hamilton replaced Schumacher and finished the season fourth overall to Rosberg’s sixth.

*In 2013, Rosberg won the Monaco Grand Prix exactly 20 years after his father had triumphed there.

*Rosberg was championship runner-up to Hamilton in 2014 and 2015 but ended the year strongly with three straight wins.

*In 2016 he fought Hamilton in a title battle that went down to the final race of the season and won by just five points to become only the second son of a Formula One champion to win the title, after Damon Hill. Hill took his 1996 title 34 years after father Graham first became champion in 1962. Rosberg’s came 34 years after Keke’s success.