Spartak Moscow passed up the chance to move top of the Russian Premier League standings as they went down 1-0 at struggling Terek Grozny.
The visitors could have gone two points clear at the summit, with fellow title challengers Zenit St. Petersburg and Lokomotiv Moscow not in action until Sunday and Monday respectively.
But Mauricio's goal in the opening minute put paid to those hopes, with Spartak unable to break down a resolute Terek defence thereafter.
The result left Spartak in third position - a point behind Zenit and Lokomotiv - while Terek climbed one place to 13th courtesy of their third win of the season.
In Saturday's other game, Ural climbed one spot to 14th thanks to a 1-0 triumph at sixth-placed Krasnodar, Gerson Acevedo netting the decisive goal in the 19th minute.