The defending champions PSG looked to be heading for their first loss of the Ligue 1 season after conceding goals to Benjamin Corgnet and Romain Hamouma.
But the dismissal of Fabien Lemoine allowed PSG a route back into the match and they responded with a volley from Edinson Cavani, before Matuidi's late heroics claimed a point which lifts Laurent Blanc's team back to the top of the table.
Monaco had moved top for a few hours earlier following their 2-1 victory over Lyon.
Claudio Ranieri's side moved one point above PSG, whose draw moved them back to the summit on goal difference.
Mounir Obbadi and Falcao were on target in the first half for the home side, while Bafetimbi Gomis netted his second goal of the season midway through the second half for Les Gones.
Bordeaux continued their improved form with a 2-0 victory over 10-man Montpellier at the Stade Chaban Delmas.
Cheick Diabate and Ludovic Obraniak were on target with second-half goals as the home side made it three wins in their last four games in all competitions while extending their unbeaten league run to six matches.
Montpellier lost Yassine Jebbour to a red card midway through the first half and the defeat drops them below Bordeaux to 15th in the table as they have recorded just one win in their last eight matches.