Edinson Cavani came off the bench to add a second from the penalty spot with little over 10 minutes remaining, his third league goal of the season, as PSG reclaimed top spot until Sunday evening at least.
Defeat for Toulouse leaves them languishing in mid-table as Alain Casanova's men failed to make it three league wins on the bounce following victories over Lorient and St Etienne.
PSG top the table by one point from Monaco - who travel to Reims on Sunday - and Marseille, who were 2-0 winners away to Lorient.
Mathieu Valbuena celebrated his 28th birthday with a superb second-half free-kick to fire his team ahead before Andre Ayew struck in stoppage time to wrap up all three points.
Lorient have managed only two wins over Marseille in Brittany in 11 attempts and defeat for Christian Gourcuff's men on Saturday means their early-season unbeaten home record is now at an end.
Lille are hanging on to fourth place after a goalless draw away to Lyon, but Nice have moved level on points with a 1-0 win over Guingamp, Dario Cvitanich heading in unmarked from a free-kick in the 48th minute.
That moved them above St Etienne, who conceded two late goals to draw 2-2 at home to Bastia - the controversial equaliser arriving four minutes into time added on.
The hosts took the lead through Franck Tabanou's volley in the 27th minute and were cruising when Ismael Diomande fired in a powerful effort just before the hour mark.
But with time counting down, Gianni Bruno scored an 85th-minute goal for the visitors and Francois Modesto claimed a late, late equaliser - with strong suspicions of offside - in almost the last action of the match.
Check Diabate's second-half equaliser denied Evian a first-ever victory over Bordeaux in Ligue 1 in a 1-1 draw that kept both clubs looking over their shoulders in the lower reaches of the table.
Kevin Berigaud scored in the 26th minute to give Evian hope of ending their hoodoo, but Diabate's goal 20 minutes from time ensured the spoils were shared.
There was further drama with the dismissal of Maxime Poundje 10 minutes from time but Evian could not take advantage.
Quickfire early goals gave Sochaux a 2-0 win over Valenciennes.
Cedric Bakambu fired in the first in the 12th minute and Carlao doubled the lead six minutes later from a corner.