By Alan Baldwin
SOCHI, Russia (Reuters) - Triple world champion Lewis Hamilton is the only Formula One driver to have won the Russian Grand Prix and, with Mercedes team mate Nico Rosberg on a red-hot winning streak, needs to keep it that way on Sunday.
The Briton will be toiling flat out on May Day, the international workers' holiday, to deny his German rival a seventh successive win and fourth of the sport's longest ever season.
Hamilton won the inaugural race around the 2014 Winter Olympic Park and returned last October to repeat the feat after Rosberg had secured pole position but then retired with a throttle failure.
While that victory set Hamilton up for the title, which he took in Texas two weeks later, Sunday's race has been moved to the Russian national holiday slot with the 2016 championship still in its infancy.
Hamilton is already 36 points behind Rosberg and while he is unlikely to be sending out any Mayday distress signals the Briton is in definite need of a track turnaround.
"There was plenty going through my head after China, as you'd expect," he said after starting that third race of the season at the back of the grid and finishing seventh.
"But, after all these years, experience has taught me to stay calm and keep pushing forwards when I get knocked back. I've been here before a few times now.
"Adversity is part of the journey," he added. "There are lots of positives to carry into the next battle. If nothing else, I know after these first few races that I can still overtake."
Rosberg has not had to do much of that recently, leading from pole in Shanghai and also enjoying comfortable wins in Australia and Bahrain.
Hamilton was also on for a hat-trick of wins in Bahrain and China, having won both races there in 2014 and 2015, and Rosberg denied him both.
But the German remains wary of what might happen.
"I would never have expected the first three weekends to go the way they have," said Rosberg.
"I've made the most of my opportunities and I have a bit of an advantage in the points right now -- but we are only three races down and it would just take one bad weekend for that gap to disappear.
"I was looking good all weekend last year until a technical problem put me out of the race and I had great fun fighting from the back the year before, so I know I'm competitive at this track."
Both Mercedes drivers can expect to be pushed hard by Ferrari's Sebastian Vettel and Kimi Raikkonen but they also need to worry about Red Bull's Australian Daniel Ricciardo and local hero Daniil Kvyat.
With impeccable timing, Kvyat finished third in China for his second career podium appearance after Ricciardo had qualified on the front row.
Conditions are expected to be fine all weekend, with temperatures of around 18 degrees Celsius.
(Editing by Peter Rutherford)