Valtteri Bottas will stay at Mercedes for another season, the team has officially confirmed.
Bottas joined Mercedes at the start of this year as a short-notice replacement for Nico Rosberg. Rosberg retired five days after winning last year's world championship. However, the Finn was only given a one-year contract. That led to suggestions he was just a stop-gap, with the team eyeing a bigger name for 2018.
Instead, in 13 races with the team so far Bottas has outperformed all expectations. He's scored 197 championship points so far and claimed two race wins (Russia and Austria) and two pole positions (Bahrain and Austria again).
"We gave Valtteri a big challenge this year," said Mercedes team boss Toto Wolff on Wednesday. "Joining the team at the eleventh hour. Stepping up to the forefront of Formula 1. And pairing with the sport's best driver as his team-mate.
"With that in mind, his results have been probably even more impressive.
"There have been ups and downs - more ups, fewer downs. And some great highlights like his two race wins in Russian and Austria.
"Overall, the balance of his performances and his upward trajectory made it a no-brainer for us to continue with him into 2018.
"For our team, the bonus factors are the respect and sportsmanship that have grown between our two drivers. The chemistry and dynamic between Valtteri and Lewis work and are what we need to take the fight to our competitors."
Bottas said he was delighted to be staying at Brackley for another season.
"I am honoured and proud to continue to work with Mercedes-AMG Petronas Motorsport in 2018 and to remain part of the Mercedes family. Together, we continue to grow stronger day by day. By keeping up our hard work I believe the sky is the limit."
"Since joining the team in January, I've enjoyed every day working with them," he added. "When the team hired me for the 2017 season, they took a leap of faith by putting their trust in my skills.
"This new contract for 2018 shows that I've earned that trust.
"I want to thank all the board members, the people at the factories in Brackley and Brixworth as well as the race team and all the fans for their support and trust. It means a lot to me."