Lewis Hamilton knows he faces a tough challenge to stop championship leader Sebastian Vettel winning the Hungarian Grand Prix on Sunday after qualifying fourth.

Hamilton has been off the pace in Hungary this week as Ferrari have set the standard and he was unable to revitalise his fortunes on Saturday, despite briefly going fastest in Q2.

His attempts to maintain that speed into the final session failed to materialise, Vettel going even faster while Hamilton came off at turn four on his first attempt at a fastest lap.

When he returned the Mercedes driver could only finish five tenths behind Vettel and, given the difficulty in overtaking at the Hungaroring, he knows winning will not be easy.

"It's not been the easiest, most straightforward weekend," he told Sky Sports F1.

"The car felt pretty good, we made some improvements in qualifying and the laps were generally good apart from Q3.

"We knew they [Ferrari] were quick and we were aware of their pace. I don't know if they brought an upgrade but I think we did quite well considering.

"You can't overtake here so it's most likely going to be a train unless we can do something on strategy."

While Hamilton, who is one point behind Vettel in the title standings, was downbeat about his chances, team-mate Valtteri Bottas retained a glimmer of hope after out-qualifying the Briton.

"Ferrari have been quick all weekend," he said. "We knew qualifying would be close and they'd be tough to beat and they had the upper hand. 

"They've clearly got everything right for this track and we've still got work to do for tracks like this. But let's see tomorrow.

"Clearly we are not performing as we want here. But it will be a long race and anything is possible."