McGinn had last scored on December 21, but the Northern Ireland international struck seven minutes after the break to level the scores as the second-placed Dons shared the points with their north-east rivals, pegging back an early opener from his international team-mate Paul Paton.
The 26-year old said: "I'd nearly forgotten how to score! It's great to score a goal again and there was a bit of joy and relief.
"I've been getting chances in the last few games and I've always felt I could chip in. Hopefully that will kick-start the scoring and I'll get a few more goals between now and the end of the season."
McGinn was swamped by team-mates as he raced towards the halfway line following his goal, and the emotions he was feeling were clearly on show.
He said: "All the boys have been excellent and they were all congratulating me after the game."