Marcelo Bielsa's early pacesetters produced a superb display of attacking football on Tuesday to make it five consecutive victories in France's top flight.
Gignac opened the scoring after eight minutes with a header from Benjamin Mendy's left-wing cross, and nodded home a second 11 minutes later to take his tally for the campaign to eight after Florian Thauvin had been denied by Johnny Placide.
Ayew then headed in to put the game beyond doubt after 59 minutes with two goals in the space of seven minutes, the second coming with a stunning exhibition of trickery, wrapping his left foot around the back of his right to convert a rebound following more good work from Thauvin.
And a marvellous showing was capped off in the 74th minute by a fierce long-range strike from midfielder Giannelli Imbula.
Meanwhile, Toulouse made it just one win in five for Rennes with a fine 3-0 away success at the Stade de la Route de Lorient.
Serbian striker Aleksandar Pesic broke the deadlock with his first goal for the club three minutes before the half-time interval.
Rennes coach Philippe Montanier evidently failed to inspire his players during the break as Toulouse made sure of the points with two second-half goals.
First Rennes defender Fallou Diagne deflected Tongo Doumbia's header into his own net, and then striker Wissam Ben Yedder ended the home side's hopes with his fourth of the term, continuing his strong form in front of goal after scoring 17 last season.
