Edmondson claimed the Cobblers' fourth goal in a 4-1 win over Portsmouth at the weekend, despite team-mate Sam Hoskins being credited with it.
Hoskins sent the ball over the head of Pompey keeper Craig MacGillivray and towards the net, before Edmondson got a touch a yard or so out.
His 'insurance policy' finish has earned him the goal and ended his wait to get off the mark for the League One outfit.
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Edmondson told the YEP when he secured his second loan of the season, following a spell with Aberdeen, that he wanted to add goals to his season.
"I used to be this big lumpy target man as a number nine but over the past couple of seasons at Leeds I've developed variations to my game," he said.
"My main one is my work ethic, I'm a bit of a running horse, I just run around, pressing the back line, running in behind, I like to vary it. I want to score as many goals as I can, be a presence in the box. I think they've just been lacking a finishing touch so hopefully I can add that."
The 19-year-old has played a dozen times for Northampton since his arrival. They travel to Charlton Athletic tonight.