Zenit St. Petersburg crushed FC Krasnodar 4-0 on Saturday to take a seven-point lead into the Russian Premier League's three-month winter break.
Zenit coach Andre Villas-Boas said the win boosted the club ahead of Tuesday's Champions League match at Monaco, which Zenit must win to qualify for the knockout stages.
"It's a very important win for us," Villas-Boas told Russian media. "We wanted to go into the Monaco game with just this kind of attitude."
Zenit's win in the snow in St. Petersburg was an emphatic performance after weeks of indifferent form, with three defeats in its preceding five matches.
Villas-Boas' team went ahead through Ezequiel Garay's 11th-minute opener, the Argentinian defender scoring on the rebound after Hulk's free kick hit the post.
Krasnodar's first-choice goalkeeper Andriy Dikan had been injured shortly before Garay's goal, and a blunder by his replacement Andrei Sinitsyn was responsible for Zenit's 55th-minute second goal.
With smoke from flares restricting visibility, Sinitsyn failed to cope with a cross from deep by Igor Smolnikov, palming it into the path of Axel Witsel, who scored easily.
Miguel Danny made it 3-0 to Zenit with a fine strike seven minutes later, before full back Igor Smolnikov scored off a pass from Hulk on 68 minutes.
Defeat leaves Krasnodar third, although the team from southern Russia could finish the year in fifth place depending on Sunday's games.
Defending champion CSKA Moscow scraped a 1-0 win away to Kuban Krasnodar, thanks to a goal from Nigerian forward Ahmed Musa on 45 minutes.
Matching the club record by making his 426th league appearance for CSKA, goalkeeper Igor Akinfeev had little to do against poor finishing from Kuban's players. Igor Armas should have scored for Kuban on 18 minutes when presented with an open goal, but hit the post.
CSKA travels to Germany to face Bayern Munich on Wednesday in its final Champions League group game. In order to qualify, CSKA must win and hope that Roma does not beat Manchester City.
The 17th round in the 30-match Russian league season concludes Monday, with action resuming in March after the winter break.