Russian league leaders Zenit St Petersburg, who have found a fresh lease of life under new manager Andre Villas-Boas, have an excellent chance to extend their advantage when they take on lowly Volga this weekend.
Zenit, who have a perfect record under Villas-Boas' tenure so far with five wins from as many matches, are a point ahead of second-placed Lokomotiv Moscow.
Volga Nizhny Novgorod, who are battling against relegation, earned a hard-fought 2-1 win over Rostov last week for their first win since October 20.
But Villas-Boas said any side in the Russian league can cause problems for top clubs who refuse to take them seriously.
"Our previous match with bottom-placed Anzhi was really hard as they're are a well-organised and uncompromising team and the home win was their last chance to avoid relegation," he said.
"Volga, who still have chances to stay in the top flight, desperately need points and we shall be cautious to avoid unnecessary troubles on Saturday.
"We're set to win the league this season to set up a foundation for our further movement ahead in European football. Zenit is an ambitious club and it was one of the main reasons for me to take over them."
Meanwhile, Lookomotiv face a tough test away to sixth-placed FC Krasnodar, who are aiming for a place in next season's Europa League.
In-form Krasnodar, who battled back from a goal down to earn a morale-boosting 2-1 away win over Dynamo Moscow on Sunday, look capable of upsetting any of their domestic league rivals.
But railway-backed Lokomotiv, who also came from behind for a 2-1 win over Terek Grozny last week, will be able to call on Senegalese marksman Dame N'Doye after he sat out a one-match ban against Terek.
- Focused throughout -
"We were without a set of our first-line players but the team proved that they can battle and win even in a desperate situation," Lokomotiv head coach Leonid Kuchuk said.
"My guys remained focused throughout the match with Terek. Now we have no other choice but to repeat this kind of performance in Krasnodar to stay in the race for the title. I hope we are capable of doing that."
Reigning champions CSKA Moscow, who thrashed Kuban Krasnodar 4-0 on Sunday to extend their winning streak to six matches, will also have to overcome tough opponents in Rubin Kazan to keep their chances of retaining their title alive.
CSKA manager Leonid Slutsky said: "We're not working out any long-range plans or strategies.
"We try to focus on our every single match to get as many points as possible, expecting also for slip-ups by the league leaders.
"I hope that Nigerian Ahmed Musa and the Swede Rasmus Elm, who have missed our match at Krasnodar, will be able to strengthen us against Rubin."
Samara v Amkar Perm
Ural Yekaterinburg v Tomsk, Zenit St Petersburg v Volga Nizhny Novgorod, FC Krasnodar v Lokomotiv Moscow
CSKA Moscow v Rubin Kazan, Rostov v Anzhi Makhachkala, Terek Grozny v Dynamo Moscow
Spartak Moscow v Kuban Krasnodar