The Dons started the game with only one Scottish Premiership win to their name this season, but they dominated long spells and managed to turn that into goals after a goalless opening 45 minutes.
Thistle midfielder Stuart Bannigan fired a decent effort just wide of Jamie Langfield’s goal in the early moments but Aberdeen always looked dangerous and Peter Pawlett put in a couple of lovely crosses that were close to being converted by on-rushing strikers.
Paul Gallacher made a decent save from a McGinn shot from the edge of the box and Aberdeen thought they had won a penalty when Ash Taylor went down in the area – nothing was given though.
The Dons continued on the front foot with McGinn again denied by Gallacher and Shaleum Logan’s inviting cross failing to earn anything more than another corner.
Half-time, just as in the other four 3pm kick-offs, came and went without a goal but Aberdeen finally made the breakthrough two minutes after the interval when Low curled a shot past Gallacher from the edge of the box.
With the rain beating down, Aberdeen pushed for a second and David Goodwillie saw an effort trickle past the post.
At the other end, Langfield had to be alert to push away a shot from Kallum Higginbotham, but the second home goal came on 66, and what a stunner it was from McGinn as he picked the ball up outside the box and lashed an unstoppable strike past a helpless Gallacher.
The Dons suffered an injury blow when the influential Jonny Hayes limped off with just over 15 minutes remaining but they finished strongly with sub Barry Robson hitting the bar as they secured their first home win of the season.