Championship minnows Annagh United defeated Glenavon in a penalty shoot-out after the League Cup second-round game ended 3-3 at Mourneview Park.
Chris McElroy gave Annagh an early lead before Andrew Hall levelled.
Kevin Braniff's superb strike and a Declan O'Brien header made it 3-1 but Annagh hit back with late goals from Jordan Campbell and Stephen Acheson.
Mark Robinson saved three Glenavon penalties in a dramatic shoot-out, which Annagh won 3-2.
Glenavon dominated affairs after McElroy side-footed in from Stephen Park's cross in the third minute to put the Portadown visitors ahead in the Mid Ulster derby clash.
Braniff's back-heel pass set up Hall to fire in on 15 minutes and the same two players were involved in the third goal of the game.
This time Hall was the creator with Braniff smashing into the top corner.
Mark Patton hit a post for the Lurgan Blues before O'Brien opened up a two-goal cushion seven minutes into the second half.
A loss of concentration on two corners was to to prove costly for Glenavon, with Campbell's header on 80 minutes quickly followed by a similar finish from Acheson.
It remained level after extra-time and Annagh prevailed in the shoot-out with Gary Boyle, James Gardiner and Acheson converting for United, who will take on Ards in the third round.