Lewis Hamilton admitted he underperformed throughout the Chinese Grand Prix weekend after having to settle for fourth position.
Many had expected Mercedes return to the front in China but the world champions struggled for pace and were comfortably beaten to pole by Ferrari. Hamilton was out-qualified by teammate Valtteri Bottas and then lost out to Red Bull's Max Verstappen at the start.
Mercedes missed the opportunity to mirror Red Bull's race-winning strategy at the Safety Car period, meaning Hamilton was easily passed by Daniel Ricciardo in the closing stages.
"I was in no man's land today," Hamilton said after the race. "I had no pace. I was just trying to hold on for whatever I had."
Mercedes has failed to win any of the first three races of this season, its longest victory drought since the introduction of the V6 turbo engines in 2014. Ricciardo's win means Red Bull and Ferrari have both claimed a win before Mercedes in 2018 and Hamilton knows he will need to improve to stay in championship contention.
"It's a tough battle ahead of us, particularly on my side, I would say my side, but also us as a team.
"We've been underperforming. Yesterday and today have been a disaster on my side, so I've got to try and rectify that and try and get back into normal performance mode, otherwise more valuable points will be lost. I'm thankful a couple of incidents that happened ahead today kept us in the battle."