Hamilton seeks to tighten title grip with fifth consecutive Russia win

Defending champions Lewis Hamilton and Mercedes will seek to tighten their grip on this year's Formula One world championship with a fifth triumph in five years at the Russian Grand Prix.

No other team has tasted a 'vodka-laced' victory since the event began at the former winter Olympic Games venue in 2014, Hamilton winning then and in 2015, Nico Rosberg in 2016 and Valtteri Bottas last year.

And with a 40-point lead on Ferrari's Sebastian Vettel in the title race, four-time champion Hamilton looks set to go into the final six races of the season in confident fashion after registering four wins in his last five outings.

Mercedes team boss Toto Wolff, however, has warned against complacency as they enter the championship's most critical spell.

Hamilton's dazzling triumph in Singapore, where his pole lap was widely regarded as one of the greatest of all time, may have lifted him into a position with a clear advantage, but Wolff has stressed that rivals Ferrari will be a serious threat in every contest.

"Obviously, it's better to have a lead than not to, but there are six races to go and plenty of points to score -- so it doesn't give us any comfort," he said.

"We will continue to concentrate on every single session, trying to optimise the car in every possible area -- and we will go for the race win.

"There is no naive optimism about our situation within the team.

"Our mind-set is very positive, we are energised, the factories are buzzing and we're excited for the fight that we will certainly have in the next six races.

"We have a good track record in Sochi, but we know that Ferrari and Red Bull will give it everything to break our winning streak so we must fight as hard as ever."
- 'Bottas work ethic' -
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"But luck isn't a one-way street and I know Valtteri has every ingredient required to win at this level. He needs to work hard and trust that the tables will turn for him."