Jamie Arnold led the way for Virtus with 22 points and 11 rebounds as they qualified for the next phase of the competition.
In the first game between the two sides back on November 26, Virtus only beat Oostende 70-69.
Matteo Boniciolli, the coach of Virtus, said: "The difference between the first game against Oostende and this game is that the first game also was one of my first games as coach (of Virtus).
"We have been working hard since then and improving a lot."
Virtus trailed 7-3 early on but opened up an 18-13 lead at the end of the first quarter.
Lionel Bosco's jump shot tied the game at 20-20 early in the second quarter but Virtus found their rhythm and Arnold's three-ball at the end of the second quarter gave them a 46-36 half-time advantage.
Oostende fought bravely and kept the game close.
They closed the gap to three points in the third and finally early in the fourth managed to tie the game at 65-65 on a Bosco three.
Arnold hit a jump shot to put Virtus back in front and they stayed on top for the final 8:22, ultimately winning by 11.
"We knew it was going to be a tough game," Arnold said. "We knew it was going to be war. It feels great to qualify."
Jamie Arnold, player Virtus:
"We knew it was going to be a tough game. We knew it was going to be war. It feels great to qualify."
Matt Haryasz, player Base Oostende:
"I have to give great credit to Bologna. They played a great game. We still have a chance to qualify in the next two games but it is going to be difficult."
Matteo Boniciolli, coach Virtus:
"The difference between the first game against Oostende and this game is that the first game also was one of my first games as coach [of the team]. We have been working hard since then and improving a lot. I want to congratulate Oostende and the coach for their fighting spirit. Oostende is in a difficult period now and the only way to get out [of it] is to work and play hard as they did tonight. Jamie Arnold played a great game tonight, as well from the three-point line as one on one, getting a double double. That gave Oostende a lot of trouble in rotation. Everybody did a great job and when that many players get double figures, you know we can compete on every level, in Italy as well as in Europe."
Umberto Badioli, coach Base Oostende:
"I want to congratulate Virtus but also my team. We tried to play tough and control the rhythm as that is the only way to compete against a talented team as Bologna. We played hard but lacked toughness on rebounds losing both halves. We also had to introduce a new guard and then it is not easy to play against a well organized team as Bologna."