Lewis Hamilton admits he has work to do in a "tough battle" for the 2018 Formula 1 world championship after enduring what he called a "disaster" of a Chinese Grand Prix. 

Mercedes was tipped as early favourites for victory in China heading into the weekend, having dominated at the Shanghai International Circuit in recent years, but the reigning world champions struggled in qualifying and finished 0.5s adrift of polesitter Sebastian Vettel. 

Hamilton, who qualified fourth, lost out to Red Bull's Max Verstappen at the start and ran in fifth for much of Sunday's race, until a mid-race Safety Car flipped the battle at the front on its head. Both Mercedes and Ferrari drivers remained out while Red Bull gambled on double-stacking its cars to switch onto fresher soft tyres. 

After running as high as third, Hamilton was quickly passed by race-winner Daniel Ricciardo and Verstappen, but gained fourth place back after the Dutchman was handed a 10-second time penalty for colliding with Vettel. 

"I was in no man's land today. I had no pace," Hamilton told Sky Sports F1. "I was just trying to hold on for whatever I had."

Despite his somewhat quiet race, Hamilton was able to cut the deficit to early championship leader Vettel to nine points, after the German was turned around following a hit from Verstappen at Turn 14, before dropping back to eighth place. 

When asked how he sees the title fight shaping up after Mercedes failed to take a win in the opening three races of a season for the first time in the V6 hybrid era, the Briton replied: "I'm not quite sure to be honest. 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."