Russian Premier League table-toppers CSKA Moscow slumped to a 2-0 defeat at Rubin Kazan on Sunday.
CSKA could have moved six points clear at the top of the league with just four matches to play had they earned victory, but they were frustrated in Kazan.
Venezuelan Salomon Rondon – who signed from Malaga in the off-season – opened the scoring four minutes into the second half for Rubin.
And Roman Eremenko sealed the win nine minutes from time for fifth-placed Rubin, as CSKA Moscow’s title hopes took a hit.
They are still three points ahead of second-placed Zenit St. Petersburg but with just one win in their last four matches in all competitions, will be nervous ahead of the season’s end.
Zenit had to come from behind to get a point in a 2-2 draw at Kuban Krasnodar that keeps them within touching distance of the league leaders.
Konstantin Zyryanov scored for the 2008 UEFA Cup winners after just six minutes, but goals from Daniel Niculae and Ivelin Popov before half-time gave Kuban Krasnodar a 2-1 lead at the break.
Portuguese midfielder Danny levelled with 24 minutes left for Zenit though, as they claimed what could be an important point.
Third-placed Anzhi Makhachkala lost 2-0 at Spartak Moscow, who scored through Swedish midfielder Kim Kallstrom and Dmitry Kombarov.
Mordovya Saransk lost for the third match in a row as German striker Kevin Kuranyi netted a double in Dinamo Moscow’s 3-1 win, while Lokomotiv Moscow defeated Rostov 3-1.
Elsewhere, Terek Grozny edged Amkar Perm 2-1 while Volga and Krylya Sovetov played out a 1-1 draw.