Former Shamrock Rovers striker Gary Twigg marked his Portadown debut by scoring the winning goal at home to Donegal Celtic.
Twigg headed in on 50 minutes after Sean Mackle fed Chris Casement who lobbed over the cross from the right.
"It was great to score on my debut but the most important thing was getting the three points," said Twigg.
"Portadown have ambition and this should get us closer to the top six which is where we want to be."
After the goal, Portadown pushed for a second but Donegal Celtic goalkeeper John Connolly made a fine save to turn Tim Mouncey's header over the bar.
DC brought on the transfer-listed striker Mark Miskimmin and he led their attempts to salvage a point.
However, Ronnie McFall's men secured a third successful home win and they remain in seventh place but are now just three points behind Ballinamallard and a place in the top half of the table.