The Ferrari driver sits at the top of the Championship after achieving his second win of the season in Bahrain, a fortnight ago after also winning the opening win in Australia. His nearest rival, Hamilton, won the other, the extremely wet Chinese Grand Prix.
With the Briton just seven points behind him, the four-time Champion is aware that any advantage is crucial - no matter how small or close that may be.
Vettel was talking ahead of the race at a circuit where Mercedes have won all three races in its post-war history.
Vettel, Kimi Raikkonen, Sergio Perez and Valtteri Bottas the other drivers to make the podium with Williams the second best performers at the track with 49 points compared to Mercedes' 11.
The 29-year-old said: "That would be nice for us. On paper Mercedes is the clear favourite, as the Sochi track is a circuit made for Mercedes - so the closer we can get the better. So let’s see.
"There is a lot of work to do tomorrow to bring the car into a grid position that will help us. I like this track, so that is a good start for a day with a huge workload."
After several years of not challenging for the title, Vettel is now back to fighting at front of the pack and him and Hamilton seem to be enjoying their new rivalry.
He added: "Two out of three [races won] - that sounds pretty good! But let’s not get greedy. I am so happy with where we are - especially the pace that we’ve shown in all three races that was a match with Mercedes - and that on two Sundays we’ve had the upper hand."
None of the other driver's or teams will want the title to be a straight two-car race between Vettel and Hamilton, who have seven titles between them, but they will need to start winning races sooner rather than later to prevent that from happening.
There will be some positivity in the paddock after Bottas and Raikkonen, their respective teammates, were first and second in practice one.
It will be interesting to see if the two Finn's can transfer that to the race track