A dejected Lewis Hamilton admitted that he needs to rediscover his speed after an abject display in Russia saw him fall further behind rival Sebastian Vettel in the championship race.
As Hamilton toiled to fourth, his new Mercedes team-mate Valtteri Bottas clinched the first victory of his Formula 1 career at the 81st attempt, as he became the third winner in four races of this unpredictable season.
“I can’t explain it right now, but we will do some work over this week to fully understand it,” Hamilton said.
“It is not important to think about the championship because I need to understand where the speed was this weekend, where I went wrong with the set-up, and then come back fighting for the next race.
“There is still a long way to go. I am still second in the championship, so it is not the end of the world, but of course I need to recover the pace that I had previously because it was a very, very unusual weekend.”
Bottas arrived at the fourth round of the championship facing question marks over his position at Mercedes after he was ordered out of Hamilton’s way in Bahrain.
But the 27-year-old, who was plucked from Williams to fill Rosberg’s championship-winning seat only in January, responded in exemplary fashion and must now be considered as a real threat, not only to Hamilton and his de facto No 1 status at Mercedes, but perhaps Vettel, for this year’s title, too.
“For me winning the championship is the only goal in my career so we will keep pushing for that,” said Bottas, who received his winner’s trophy from Russian President Vladimir Putin.
“I am not that emotional but hearing the Finnish national anthem is something quite special.”