CSKA won the fourth quarter with a difference of "+10", but could not at least transfer the meeting to overtime.
The most productive among them was the American Mike James, who scored 20 points.
Despite the setback, CSKA remained on the first line in the standings with 14 wins in 18 matches.
Basque Country is in eighth place.
Earlier it was reported that Zenit defeated Panathinaikos in the Euroleague match.