A headed goal from Obafemi Martins gave Rubin a 1-0 win over Anzhi on Sunday, taking the Kazan side to fifth in the Russian Premier League.
The Nigerian scored on 50 minutes, beating ex-Blackburn Rovers defender Christopher Samba to Cristian Ansaldi's cross.
The victory, Rubin's first since a 2-0 win over Dynamo Moscow in November, lifts them above Anzhi and Dynamo Moscow, who play Lokomotiv Moscow later Sunday.
Anzhi, who failed to create any clear chances, drop to seventh.
Rubin coach Kurban Berdyev defended his side's caution after goal.
"After the goal made it 1-0, the lads just played to see out the result. The important thing for us today was the result."
Guus Hiddink's side have seven games left to mount a challenge for one of the top three Champions League qualification spots, lingering four points adrift of Lokomotiv in third.
The first half offered few chances, with Martins sending two soft efforts at Anzhi goalkeeper Vladimir Gabulov.
Rubin’s Alexander Ryazantsev sent a long-range effort over the Anzhi bar on 44 minutes.
In first-half stoppage time, a divot on the pitch meant that Gabulov fumbled a routine back pass and was forced to pick it up to prevent an easy Rubin goal.
Bibras Natkho took the resulting indirect free-kick inside the box, but saw his ball cleared by Samba.
Five minutes after the restart, Ansaldi had space on the left flank to swing in a curling cross, which Martins headed in from close range.
Samba had been marking the former Newcastle United man, and berated the Anzhi defense for failing to intercept the cross.
Anzhi struggled to respond as Rubin continued to control possession, although Eto’o managed a shot at goalkeeper Sergey Ryzhikov on 58 minutes, the Caucasus team’s first effort of the game.
Samba came close on 69 minutes, looping a header over the bar with Ryzhikov stranded.
Paraguay striker Nelson Haedo Valdes almost extended Rubin’s lead on 70 minutes when he beat Samba with a flick to go clear on goal, but Gabulov saved his shot with ease.
Samba charged forward in the dying minutes, attempting to use his aerial prowess against the Rubin defense, but failed to connect with a 90th minute cross when in a good position.
Earlier Sunday, Terek Grozny gifted Amkar Perm a 2-0 win thanks to two defensive slip-ups.
On Saturday, Zenit St. Petersburg took a big stride toward the title with a 2-1 win at Spartak Moscow, going nine points clear at the top, and FC Volga climbed to 12th with a 2-0 win over Rostov.
On Friday, FC Tom Tomsk ended months at the foot of the table as their 2-0 win at Spartak Nalchik lifted the Siberians to 15th.
