Carlo Ancelotti's side secured a comfortable win into the last 16 as they paid tribute to performance director Nick Broad in a subdued home fixture at the Parc des Princes
Kevin Gameiro opened the scoring, before Franck Tabanou equalised soon after. Further efforts from Javier Pastore and Ezequiel Lavezzi ensured victory, as the capital club seek to repeat their winning cup success of 2010.
Carlo Ancelotti rang the changes with Kevin Gameiro replacing the suspended Zlatan Ibrahimovic as Sylvain Armand reverted to centre-back after the injuries sustained to Thiago Silva and Alex.
For Toulouse coach Alain Casanova, Etienne Capoue started at the back, with reported Newcastle and Olympique de Marseille target Moussa Sissoko dropping out of the squad altogether after a fall-out.
The hosts started brightly, and could've taken the lead inside the first minute. A sumptuous lofted ball from Blaise Matuidi saw Lavezzi control the loose ball expertly with his chest, but the half volley would be fired narrowly over by Olivier Blondel.
It wasn't long before les Parisiens seized the initiative though. Capoue, who has looked rather suspect in his makeshift position, failed to track the run of Gameiro, who turned in from Lavezzi's fine low pass into an empty net to nudge his side ahead.
Ancelotti's men were dominating in the early stages, as the visitors struggled. An unsuccessful counter-attack from Pastore however, would see Toulouse hit back. Le Tefece ploughed forward in numbers, with a brilliant cross headed in by Tabanou after 17 minutes - his third goal in two games after a double in the league win over Nancy at the weekend.
The Parisian side rallied after that setback, and should've regained the lead towards the end of the first half. A dipping Gregory van der Wiel cross was met powerfully by Pastore, who was denied by Blondel, with the second-choice goalkeeper thwarting the Argentine once more, just seconds later.
Toulouse were forced to weather the storm as PSG continued their unrelenting pressure. Mamadou Sakho somehow managed to hit the post with a header just inches out, before defensive partner Armand flashed a shot into the side netting from distance, as the level of frustration around the ground grew.
Ancelotti addressed his side's frailties by sacrificing Gameiro in favour of Jeremy Menez, and the plan came to fruition within three minutes of the re-start. Menez's defence-splitting pass enabled Pastore to strike at Blondel's near post, as PSG roared back into the lead.
Tabanou again threatened at the other end, after a dipping Aurier cross was mis-hit by the left-sided midfielder, as Toulouse searched for another equaliser. However, they were soon dealt a further setback as their defence finally started to crumble.
Menez's impact as a substitute was telling, and he picked up another assist, threading a neat pass towards Lavezzi. The former Napoli star calmly dinked the ball over Blondel to all but seal the eight-time winners' passage to the last 16.
PSG host Lille on Sunday as Ligue 1 action resumes, whilst Toulouse continue their push for European football when they travel to Reims.