The defending champions looked on as third-placed Marseille drew level on points with them courtesy of a 6-1 demolition of Toulouse on Friday night.
Laurent Blanc's men found an impressive showing of their own as David Luiz, Zlatan Ibrahimovic, Blaise Matuidi and Javier Pastore were all on target.
Yoann Touzghar provided a small crumb of comfort of Lens, who remain second bottom and nine points from safety.
Lyon travel to Montpellier on Sunday, where a victory would restore them to top spot with a single-point advantage over PSG.
Although probably a touch too distant to make an impression on the title race, Monaco kept their UEFA Champions League qualification ambitions burning with a 3-1 win at Evian.
Leonardo Jardim's men were irresistible in storming to a three-goal advantage - Anthony Martial and Almamy Toure on target either side of a Kassim Abdallah own goal.
Modou Sougou ensured an Evian player netted at the right end, but they sit precariously three points above the relegation zone.
Bordeaux were forced to dig deep for a 2-1 win over Caen.
The hosts were reduced to 10 men when Lenny Nangis received his marching orders for a rash challenge on Wahbi Khazri, but Bordeaux had to wait until 69 minutes to break the deadlock.
Diego Rolan combined with Nicolas Maurice-Belay to find the finish before Sloan Privat hauled Caen level three minutes later.
There was one more twist in the tale as Dennis Appiah was penalised for handball and Rolan converted the resulting penalty five minutes into stoppage time.
Reims put welcome daylight between themselves and the bottom three by beating Nantes 3-1.
Gregory Bourillon and Aissa Mandi netted in quick succession before a nightmare first-half concluded for Nantes as Chaker Alhadhur saw red.
David N'Gog made sure his team moved six points beyond the drop zone before Ismael Bangoura pulled a goal back.
There were two more red cards in the game between Bastia and Nice at Stade Armand-Cesari Furiani - both for the visitors.
Guillaume Gillet scored a 28th-minute equaliser for Bastia after Carlos Eduardo broke the deadlock.
Nice had Gregoire Puel dismissed for a dangerous challenge on Gael Danic before Giovanni Sio brought the home faithful to their feet with what proved to be the winner.
There was further misery for Nice as Souleymane Diawara caught Mathieu Peybernes with an elbow to earn an early bath.
Elsewhere, Rennes beat basement boys Metz 1-0 thanks to a Paul-Georges Ntep goal.
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