Veteran forward Frederick Warrick scored a season-high 26 points for the Russian club, which improved to 3-2 in Group E with the victory.
Donetsk, who narrowly missed out on reaching the Eurocup, lost both of their games to Krasnoyarsk and at 2-3, they have no chance of progressing as they would lose both potential tie-breakers with Belgacom Liege and Krasnoyarsk.
Warrick had 12 points in the first half when the Russian outfit went in front for good.
The contest was knotted at 32-32 early in the second quarter after a three-pointer from Donetsk's Marque Perry.
Kaspars Kambala and Lionel Chalmers followed with jump shots for a 36-32 Krasnoyarsk advantage.
A three-point play by Warrick sparked a 6-0 run for the home side that gave it a 51-41 lead at the break.
A lay-up by Donetsk's Anthony Tucker followed by four straight points from Artur Drozdov reduced the arrears to 58-54.
Warrick replied with a three-ball and then split a pair of free-throws for Krasnoyarsk, however, who took a firm grip on the game.
Warrick was hit while attempting a shot from behind the arc and punished Donetsk by making all three free-throws to make it 75-61 at the end of the third quarter.
Donetsk got no closer than nine points the rest of the way.
Vladimir Dyachok, Chalmers and Kambala each had 15 points for the winners while Tucker poured in a game-high 32 points for Donetsk.