Paris Saint-Germain responded to Marseille's 6-1 win on Friday with a thumping 4-1 victory of their own against Lens.
Marseille's half-a-dozen against Toulouse had put them on 53 points alongside PSG in second, but the capital club's win means they now top the table by two points and go into their Champions League clash with Chelsea this week in high spirits.
Lyon go to Montpellier on Sunday and can reclaim top spot with a win, but PSG's victory -- brought about by goals from David Luiz, Zlatan Ibrahimovic, Blaise Matuidi and Javier Pastore -- threw down the gauntlet to them. Yoann Touzghar replied for Lens.
PSG were quick out of the blocks with a win imperative to their title hopes, Marco Verratti thumping the bar after 13 minutes.
The chances kept coming and Ibrahimovic crossed for Luiz whose header was kept out by Rudy Riou, while the stopper also denied Gregory Van der Wiel's cute lob.
When the opener did come 42 minutes in it was worth the wait. Luiz has it in his locker to produce the spectacular and he cracked a brilliant 30-yard-free-kick in to give his side the lead.
That was all PSG needed to kick on and they were 2-0 up on the hour. Van der Wiel was hacked down in the box by Baptiste Guillaume and Ibrahimovic did the rest from the spot.
Lens looked like they might make a fight of it with 22 minutes left, Ludovic Ball crossing for Touzghar to volley in, but that was as good as it got for them.
Eleven minutes later Pastore launched a counter attack and swung a ball in for Matuidi who did the rest into an open goal and then, with nine minutes left, Ibrahimovic set-up Pastore who volleyed in a fourth and final goal.