Les Verts led the match by two goals before Fabien Lemoine was shown a red card, which led to a PSG fightback with Edinson Cavani and Blaise Matuidi rescuing the champions a 2-2 draw at the Stade Geoffroy-Guichard.
While Blanc felt that his side weren't good enough on the night, Motta disagrees and believes that PSG performed well to earn a point.
"Saint-Etienne played well in the first half and we played well in the second," Motta told the club's official website. "So I think a 2-2 draw is the right result.
"It wasn't easy coming back against a side full of confidence after those first 45 minutes and a side leading 2-0. The team did what they had to do and earned a point tonight. It's good.
"The draw is a fair result for the match tonight."
PSG are next in action on Friday night against Lorient.