Goals from FC Dinamo Moskva's Aleksandr Kokorin and Fedor Smolov helped Russia maintain their unblemished record in UEFA European Under-21 Championship qualifying Group 6.
Wilson Eduardo put Portugal in front after 30 minutes, beating Nikolai Zobolotni from André Martins' cross. Though Pavel Yakovlev then missed a decent chance at the other end, Portugal's lead was snuffed out within six minutes of the restart when Kokorin headed past Mika from Yakovlev's pass.
Having come on at half-time, Smolov pressed Russia's advantage, beating his man before darting a shot into the bottom corner on 54 minutes. Nikolai Pisarev's side are yet to drop a point in three qualifiers, and can extend their two-point lead over second-ranked Poland when they visit Albania on 10 November.