Roman Shirokov's 89th-minute strike gave Russia a 1-0 win over Portugal in Saturday's friendly in Krasnodar.
Russia were on top throughout as Portugal struggled without captain Cristiano Ronaldo.
Artyom Dzyuba had a left-foot half-volley saved by the feet of Rui Patricio before hitting the bar with another shot, and Shirokov missed a good chance before half-time.
Goncalo Guedes had an effort for Portugal saved by Igor Akinfeev, and Fyodor Smolov's goal was ruled out for a handball.
But the game was wrapped up when Fedor Smolov's cross was touched into Shirokov's path and he buried the chance in the final minute.
Head coach Leonid Slutsky -- currently combining the national team job with his CSKA Moscow duties -- has won five straight matches since replacing Fabio Capello.