Azovmash lost the first battle at Ventspils last week but won the overall fight to earn a place in the Eurocup Regular Season.
After a 75-74 defeat in the first leg of the Qualifying Round tie in Latvia, Azovmash returned home to Mariupol and won on Tuesday, 79-65, for a 153-140 aggregate triumph.
Azovmash, who are playing without star Artur Drozdov while he serves a one-year ban for not showing up for national team duty with Ukraine this summer, were just three of 14 from long range.
But Ricky Minard hit two of those three-balls and finished with a game-high 24 points.
The game hung in the balance with 6:47 to go in the final period after two Janis Strelnieks free-throws for Ventspils knotted the second leg at 62-62.
The Azovmash defense then came to the fore, limiting the visitors to just three points the rest of the way.
A Bogdan Bayda dunk gave Azovmash a 64-62 lead and Martin Rancik was next with a three-point play to extend the advantage to five.
The Ukrainian giants held on to clinch the very important victory.
Daniel Ewing had 18 points for Azovmash while Rancik finished with 13 points and eight rebounds.
Slovenia international Hasan Rizvic was also a force for the winners with nine points, 10 boards and three steals.
Bojan Bakic led Ventspils with 18 points.
Jahmar Young, the hero of Ventspils' one-point victory a week ago, was held to 14 points on five of 13 shooting from the floor.
BC Ventspils Head Coach Gundars Vetra:
"We used a lot of power to come back in the last quarter, and we did it. But when experienced players miss their easy shots, it breaks the spirit of the team a little. Certainly, we are sorry to lose, but we will try to play much stronger in the EuroChallenge. I cannot say that the winner of this series was defined in the first game. I'm satisfied with these games because Azovmash is a team of different level. The key player tonight was Daniel Ewing. He makes complicated decisions, and for defense they are difficult to solve. Whether he misses or makes them, it's one thing, another is the result of his actions."
Azovmash Head Coach Aco Petrovic:
"Tonight we had to achieve a big result. Three of our players couldn't help us. We started the game with too many mistakes, but later resumed the control. Today Pecherov and Kolchenko played better. We let the opponents score 65 points; We still work on our defense and will win games by defense. We can defend better, but I'm satisfied with it for the moment."
Azovmash player Bogdan Bayda:
"I want to congratulate our fans with entering the Eurocup. We fought for all players who were not allowed to play for us. Not everything is great, but we are working to improve. Tonight we had our gym, our fans and that helped much."