Shay McCartan’s goal from inside his own half condemned Larne to a late defeat at Shamrock Park on Sunday.
Aaron McCarey’s own goal, after Conor McKendry had hit the post, gave Larne a first half lead, but it was cancelled out by Eamon Fyfe’s header midway through the second half.
McCartan then produced a moment of magic with two minutes left sealed the 2-1 win for Portadown.
Portadown: McCarey, D Wilson, L Wilson, Chapman, McElroy (’83 McDonagh), McCullough, Fyfe, Ukek (’77 Wylie), Obhakhan, McCartan, Thomspon
Subs: Ray, Mayse, Traynor, Mullan, Cowan
Larne: Ferguson, Want (HT Nolan), Ives, McKendry, Randall (’74 Sloan), Magee (HT Lusty), McEneff, Seary, Bolger, Gallagher (’65 Marsh), Ryan (’65 O’Neill)
Subs: Besant, Graham
Referee: Shane McGonigle