Kyle Beggs bagged a hat-trick as Glenavon ultimately swept past Portstewart at Mourneview Park to reach the next round of the BetMcLean Cup.
Despite the eventual outcome the Lurgan Blues held just a slender lead for much of the game, that opening goal coming as early as the seventh minute when Jack O'Mahony touched the ball home after Portstewart keeper Andrew Findlay failed to gather Josh Doyle's low cross from the right.
That was how it stayed until the 70th minute. On this occasion it was a James Singleton effort which Findlay kept out with Doyle on hand to tuck away the loose ball.
Beggs opened his tally for the evening three minutes after that after Ross Hunter had played him through to finish into the corner.
It was 4-0 on 78 minutes when Beggs drove home his second of the evening, although Portstewart responded almost immediately when Chandler Douglas curled the ball home after spotting James Taylor off his line.
However Beggs restored Glenavon's four goal cushion with six minutes remaining, a solo effort which saw him break through the Portstewart defence and fire inside the left post.