Rob Harker was on target before a second-half strike from one of the Clarets’ trialists secured the win to end the U23s’ training trip on a high note.
Centre-forward Harker clipped home the opening goal with almost half an hour gone as boss Steve Stone utilised 21 players to continue their fitness drive ahead of the new campaign.
Szczecin – U23 side of the Polish top-flight club – dominated the second half on their home soil and equalised through lively striker Adrian Benedyczak with an hour gone.
But the Clarets kept plugging away and were rewarded with a winner 11 minutes from time in Opalenica when youth-teamer Mitch George slotted the ball through for one of the four outfield trialists the Clarets have looked at on the trip to enjoy his moment in the sun.
In what was very much a training exercise designed to top up the week's work on the training ground, there was still a competitive edge to an encounter that produced a handful of yellow cards.
The Clarets were the better side in the opening half hour, Tunde Bayode twice offering a threat.
And the winger was involved in the opening goal, which was the best move of the day.
Full-back Joel Senior, making his first appearance in a Burnley shirt, clipped a nice pass in behind the Szczecin back four for Bayode to meet in full flight.
And his low cross was perfectly delivered for frontman Harker to meet with a neat near-post finish which he calmly tucked away.
With fatigue showing and a change of personnel after the break, the Clarets weren't as dominant again as they struggled to retain possession.
The Poles deservedly levelled when their stand-out performer punished a mistake from defender Edon Pruit to slot home.
But Burnley still had the energy left to force a winner - as well as hit a post through a further trialist - and successfully round off a productive week in upbeat mood with a victory in their opening pre-season game.
Pogon Szczecin II: Grobelny; Pach, Kuzko, Szczesniak, Kwiecien; Pawlowski, Kozlowski; Fraczak, Wedrychowski, Hostikka; Benedyczak.
Burnley (first half): Trialist; Senior, Thomas, Wilson, Glennon; Bayode, Trialist, Woods, Conn-Clarke; Trialist, Harker.
Burnley (second half): Calderbank-Park; Cropper, Younger, Pruti, Rain; Trialist, Trialist (Woods 65), N’Guessan, George (Conn-Clarke 85); Harris, Trialist.