Otto Ruoppi's goal in the second half in Kuopio last week meant KuPS traveled south with the slimmest of leads to defend ahead of their second encounter with Milsami in three seasons.
The last matchup was a UEFA Conference League Qualifying tie that concluded 6-3 in favor of the Finnish side on aggregate, but it became evident early on that a similar scoreline was unlikely tonight.
The hosts' Kabamba Kalabatama was the first to come close, but his powerful shot went wide of the post. Midway through the first half, KuPS challenged Emil Timbur in the Orhei goal, but he successfully saved Agon Sadiku's attempt.
There was a tense moment for the Kuopio team in first-half stoppage time, but Hennos Asmelash failed to direct his header properly following a great cross from Abdoul Yoda.
In the second half, Radu Ginsari had several chances, but neither he, Kalabatama, nor Nabil Khali could find the composure needed to beat Johannes Kreidl in the KuPS goal.
Milsami had 11 attempts in the second half alone, but only two forced Kreidl into action. Moreover, both came before the hour mark, allowing KuPS to gradually secure their narrow victory.
This marks the second consecutive season that KuPS has reached the Second Qualifying Round, and this time they will face Kazakhstan's champions, Kairat.