Andy Southcott opened the scoring on 20 minutes and by the interval Gunnislake had doubled their lead thanks to a Neil Kinger penalty which was awarded following a foul on Paul Tomkins.
The visitors extended their lead in the early stages of the second half. Mark Southcott won the ball and found Kinger who hit an excellent pinpoint through-ball to Tomkins who finished well.
Padstow had their best spell of the match and scored twice before Andy Wakeham converted a Tomkins centre to score a vital fourth. Tomkins added a fifth before Padstow again scored with what was almost the final act of the match.
Gunnislake have another away fixture tomorrow (Saturday) when they visit Lostwithiel.