UNICS Kazan lost 76-73 at Hapoel Jerusalem on Tuesday but won the EuroCup Qualifying Round 2 tie 161-142 on aggregate.
Hapoel led by as many as 10 points in the first quarter but were never able to seriously threaten UNICS.
Aco Petrovic, the UNICS coach, said: "We did a big part of the job in the first game when we won by 22 points. At this moment, we're in better shape.
"I'm happy we played a good game in this difficult court."
Hapoel were nevertheless happy that they had won the game.
Moran Rot, the Hapoel point guard, said: "It was important for us to win this game,
"It was a must win after we lost the last two games in a row - in Kazan and another in the Israeli league.
"We fought hard, played our best and in an aggressive way.
"UNICS is a great team with a huge budget that is very deep inside and outside. We reached a double-margin difference already, but they came back. This win will give us big motivation for the future."
Terrell Lyday had 17 points for UNICS, while Hapoel got 16 from Timothy Bowers.