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.
PJ Tucker, BC Donetsk:
"We worked well during the Christmas break but we could not play a powerful defense. Enisey is a good team with big players. Few times in the game we had problems of a mental kind, we did not get the rebounds. We came out as usual to win the game but we could not play our best throughout the game. We did not talk in defense and did not have the right communication in the game."
Ainars Bagatskis, Enisey Krasnoyarsk coach:
"I am pleased with the result which is of vital importance to us, although still very much depends on result of the other game in the group. I like the fact that we won, but I am disappointed because we let Donetsk score eighty points. They have good players and they have a new coach. This was a men's game and the guys made their shots in the most appropriate moments of the game. This was sort of a competition between Warrick and Tucker."
Frederick Warrick, Enisey Krasnoyarsk:
"It was a tough game. We tried hard and prepared well for this game. The second half of the game was much better than the first one. We played well in defense and in offense as well. The main thing is that we played as a team."