PSG had a chance on 11 minutes when Thiago Silva got above the defence to head towards goal, but Zlatan Ibrahimoivic couldn't reach the ball to convert the chance.
Toulouse continued to pressurise the Ligue 1 leaders, although the home side couldn't take advantage of their dominance.
Ibrahimovic stepped up and calmly rolled the ball down the centre of the goal to make it 1-0.
A minute later, Ibrahimovic put Lucas in on goal, but the Brazilian couldn't find the finish to give PSG a two-goal cushion.
Thiago Silva had a huge chance on 43 minutes when Ibrahimovic found him at the back post, but the defender could only shin the ball wide of the mark.
Toulouse then got a deserved equaliser through Wissam Ben Yedder, who volleyed home at the back post on 45 minutes.