Reigning Ligue 1 champions PSG were held to a goalless draw by Montpellier before the mid-season break, missing the chance to return to the top of the table.
They were knocked out of the Coupe de France by the same opponents last term and a similar tale of frustration appeared to be unfolding during an ill-tempered encounter.
Laurent Blanc's men earned breathing space 11 minutes from time with a goal from a more familiar source, Zlatan Ibrahimovic nodding home his 13th goal of an injury-affected campaign.
Lucas Moura blasted an emphatic third from a tight angle inside the box in injury time to secure a last 16 encounter with Bordeaux
The Brazilian had rifled over from the edge of the area in the 10th minute when a punted clearance from PSG goalkeeper Nicolas Douchez was shoddily dealt with.
Douchez was making his second appearance of the season having featured in last month's 3-1 win at Ajaccio in this competition. Despite some erratic early moments, the 34-year-old was largely comfortable as his defence repelled an uninspired Montpellier attack.
Montpellier's clearest chance of the match arrived in the 53rd minute but Lucas Barrios connected tamely with Anthony Mounier’s cross and Douchez collected.
Signs of PSG's swagger returned in the wake of the goal, Ibrahimovic teeing up Lucas to send a dipping half volley just over.
Montpellier's challenge was extinguished when Ibrahimovic stooped to convert a fine delivery by substitute Javier Pastore and Lucas thumped home a third early in stoppage time to add gloss to the scoreline.
