Lewis Hamilton may have extended his lead in the Formula One world drivers' championship over Ferrari's Sebastian Vettel but the Briton says Mercedes have "big problems" heading into the final five races of the season. Hamilton has a 34-point advantage over Vettel after the pair finished second and fourth respectively at the Malaysian Grand Prix but the three-time world champion was unable to convert the 70th pole position of his career into his eighth victory of the season.

The Silver Arrows struggled throughout the three practice sessions in Sepang but benefitted from Vettel being unable to compete in qualifying as Hamilton took his place at the head of the field. But the 32-year-old's lead lasted just four laps as Max Verstappen overlook him on lap four on his way to his second race win. Vettel started at the back of the grid but was able to claw his way into fourth as Hamilton stumbled to a second place finish ahead of Daniel Ricciardo.

But having suffered problems with pace for the second race in a row, Hamilton is concerned by the progress made by Ferrari and believes that despite his healthy lead in the championship, the title is far from secure with 125 points still up for grabs.

"We've done an exceptional job with what we have," he told Sky Sports. "There are some really big problems which I can't really explain to you. But we really need to make sure we rectify them for next year's cars if we really want to fight both Ferrari and Red Bull when they step up their game.

"There is a lot of work for us to do. But there's nothing we can do, it's the way the car is. People have been saying all year long that we've got the best car. It's a fact at some races that the car has turned out to be better but overall, globally, I think it's worked out that we haven't.

"Considering Vettel started last, it's not really that great to be honest. We should have won today but we didn't have the pace. I don't know which one of these next races are going to be good for us but we'll do everything we can to try and stay ahead."

Having ensured a wretched run of luck after crashing out on the opening lap in Singapore and being unable to contest qualifying at the weekend, Vettel is set for another setback after a collision with Lance Stroll on his slow-down lap after the race in Malaysia.

The FIA have decided against acting against either driver for the incident, which includes Vettel removing his steering wheel from the car and catching a lift back to the pits from Sauber's Pascal Wehlein. But the damage suffered by Vettel's Ferrari could lead to a gear-box change and an automatic five-place grid penalty for the race in Japan, unless the team can prove the contact was unforeseeable.

"We'll check [the gearbox] but yeah, for sure that could be another bad surprise this weekend," the German said. "I hope not because it was completely unnecessary. It was a sort of reflex [to take the steering wheel]. I saw Pascal was stopped and I couldn't get the steering wheel back on because the steering column was completely turned.

"Obviously the car was damaged. I put it in the seat, and it was reflex - sometimes they open the track to spectators, so I thought that's the only loose bit. Because I couldn't put it on I thought I might as well take it with me just to make sure. You don't want to lose a steering wheel. Was it necessary? Probably not."

Lewis Hamilton
Hamilton needs to win three of the last five races to become world champion again. Getty Images