Vladimír Cifranič’s side came into the tie after suffering a setback as DAC condemned them to a home defeat last week, making it three losses in all four season-deciding encounters. However, Hamza Catakovic second-minute strike set them up for a positive result in Saturday's game.
In the 15th minute, Gong doubled the lead before scoring a last-gasp goal to wrap up the victory, thus, rendering Vukan Savicevic's 69th-minute effort for the hosts a consolation.
Gong now has 10 goals in 29 games across all competitions this season. Alongside teammate Phillip Azango, the 19-year-old winger was on parade for the entire duration of the encounter while Rabiu Ibrahim who ended up on the losing side was taken off before the restart.
The win was Trencin's second in the playoff series and they are placed fifth in the log, five points adrift a Uefa Europa League spot.