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.