The Russia national team's 'White Tiger', Nikita Morgunov, drilled a shot from behind the arc with 4:04 to play in the third quarter to put Lokomomtiv Rostov in front at 57-55 and they led for the remainder of the contest.
Lokomotiv actually trailed 55-50 with 6:00 to play in the period after Vadym Matyukevych's two free throws for Sumykhimprom (1-3).
The visitors answered with 13 consecutive points, including Morgunov's go-ahead three-ball.
A pair of Matyukevych baskets finished off a 7-0 spurt to pull the Ukrainian team to within 66-64 with 8:26 to go in the game.
Fred House knocked down a three-pointer to start an 8-0 run for Lokomotiv, though, as they pulled away for good.
One reason Sumykhimprom kept the game close was their excellent 23 of 26 (88.4%) effort from the free throw line, with Lokomotiv just 14 of 21 (66.6%).
The Ukrainian team also out-rebounded Rostov 35-31.
Lokomotiv, however, made nine of 25 shots from long range compared to just five of 17 for Sumykhimprom.
House was five of 10 from the arc and finished with a game-high 26 points.
Brian Greene had with 20 points and 11 rebounds in defeat.