No.3 seed Sergiy prevailed over world no.295 Calvin Hemery 7-6 (4), 4-6, 6-2 to move into the Open BNP Paribas Banque de Bretagne Quimper challenger second round on Tuesday.
The players traded breaks twice in the opening set. Sergiy won a tie-breaker 7-4 to gain advantage.
Games went with serve until the seventh game of the second set, when the 22-year-old French qualifier made a break and held to force a decider.
A break in the fourth game was enough for Stako to seal the win after one hour and 55 minutes of play.
Stats: aces (6-7), double faults (2-3), total points won (92-88).
For a place in the quarter-finals, Sergiy faces Enrique López-Pérez of Spain.
In the doubles competition, the Kiev native will team up with Jonathan Eysseric against Indian duo of Purav Raja and Divi Sharan.