McGinn opened the scoring from a Ryan Fraser cross, while a deflected Johnny Hayes cross-cum-shot sealed the points for Aberdeen in Saturday's SPL encounter.
The former Celtic player had been better known as a winger or wide midfielder rather than a striker until he arrived at Pittodrie.
But now he has been handed a central role alongside Scott Vernon by Dons boss Craig Brown, and has become the first Red since Duncan Shearer to score in five consecutive league games.
And his scoring spree has helped take the Dons up to third in the Clydesdale Bank Premier League.
McGinn said: "I've played as a winger throughout my career, but I think having a bit natural pace helps me in supporting Scott Vernon up front.
"I'm just delighted that I'm playing every week, and it's extra special to score the goals as well.
"We've got to take confidence from every game. We lost the first game of the season, but from then we've been playing really good football.
"We had a period where we drew three home games in a row 0-0 and had we taken more points from them we could have been in an even better position.
"The main thing is that we're winning games and staying as high up the table as possible. That's the priority."