Keith Langford had 25 points and five others scored in double figures for Matteo Boniciolli's team.
Long-time Estonia international Gert Kullamäe poured in a game-high 27 points for Tartu, who dropped to 2-3.
Tartu led briefly at the start of the game.
They were on top 7-6 when Virtus Bologna's Finland international Petteri Koponen had a three-point play and put the hosts in front for good although the contest was close for the remainder of the half.
A Tanel Tein jump shot for Tartu left the Estonians trailing 42-41 with 4:08 to go in the second quarter.
Virtus closed the half on an 11-5 run for a 53-46 advantage.
A Guilherme Giovannoni three-pointer put Virtus into a 77-64 lead - their biggest of the contest - with 8:37 to go in the game.
Tartu got no closer than eight the rest of the way.
Virtus played the game without star point guard Earl Boykins, who was given permission to leave the club for a short visit to the United States.
The Italian giants had already clinched a place in the Top 16 before Tuesday's play.