The Frenchman surpassed Edinson Cavani’s tally after he netted his 139th goal in his 169th league match.
Mbappe’s goal on Saturday also added to his net goals for PSG which is now at 203.
He collected his record-breaking goal when he got a pass from Vitinha at the 31st-minute mark. Six minutes later, Vitinha doubled the lead with a long-distance strike.
Lionel Messi also scored, bringing the total to three.
Lens’ only goal was Przemyslaw Frankowski’s penalty shot.
He gained the penalty shot after PSG midfielder Fabian Ruiz did a handball. Frankowski took the opportunity and scored for Lens.
The club had created numerous opportunities to score but they were unable to make any stick, thus bringing PSG closer to their 11th league title.
PSG now has a nine-point lead with 72 points over Lens who have 63. Lens was in complete control until midfielder Salis Abdul Samed was sent off for a reckless challenge against Achrah Hakimi just 19 minutes in.
The win also eased a bit of the pressure on PSG coach Christophe Galtier who faced allegations of racist and anti-Muslim remarks while in charge of Nice last season.