Spartak Moscow moved to within one point of a record 10th domestic title when they beat bottom club Tomsk 1-0 on Saturday.
A goal by Dutchman Quincy Promes set Spartak, who are in the hunt for their first title since 2001, to a hard-fought win.
It left them 10 points clear of second-placed city rivals CSKA with just three games to go.
Spartak can claim the title on Sunday if third-placed Zenit St Petersburg, who are one point further back, fail to grab all three points at home against Terek Grozny.
"We've created plenty of chances but our finishing today was really poor," Spartak skipper Denis Glushakov said.
"Luckily we managed to score and win. We needed three points and we've got it. This is the main thing about this match."
The Muscovites, spurred by a capacity 42,000 home crowd, converted only one of a hatful of first half chances in the 15th minute when Promes converted a spotkick after Tomsk brought down Glushakov in the area.
In the second period Spartak continued to test the visitors' defence but poor finishing combined with good goalkeeping by Tomsk 'keeper Alexei Solosin left the scoreline unchanged.
Promes sent the ball into the net again with seven minutes remaining but his effort was ruled offside.
CSKA Moscow boosted their hopes of reaching next season's Champions League with a 2-0 win at Amkar Perm to leapfrog Zenit to go second.
Forward Fedor Chalov put the Red Army side in front just before the hour mark with a close-range shot after a one-two with Brazilian Vitinho in the area.
Israeli international Bebars Natcho added a goal five minutes later beating Amkar 'keeper Dmitry Khomich from 22 yards out with help of a slight ricochet.
"After an unimpressive first half we managed to regroup and score," CSKA head coach Viktor Gancherenko said. "The second goal decided the game."
© 2017 AFP