Rhys Griffiths scored on his debut as Plymouth came from behind to secure their first League Two win of the season, with Northampton beaten 3-2 at Home Park.
Alex Nicholls fired the Cobblers into a 26th-minute lead, shooting on the spin to convert Ben Tozer's cross from the left to take his tally to four goals for the season.
But Argyle fought back after the break following the introduction of debutant striker Griffiths, a summer signing from Port Talbot.
The home side were level when Warren Feeney did well to redirect Onismor Bhasera's cross from the left in off the far post with a header.
Livewire Bhasera's cross-field ball to Alex MacDonald then set up the move that led to Griffiths calmly side-footing home his first Football League goal in the 59th minute.
Griffiths' 67th minute replacement Curtis Nelson, normally a central defender, made it 3-1 with a header which looped over Cobblers goalkeeper Lee Nicholls in the 74th minute from Robbie Williams' angled cross from the left. David Artell headed home at the far post following a long throw-in from Tozer, but Plymouth held on for all three points.