Mbappe made history as he became Paris Saint-Germain’s top scorer in Ligue 1, scoring his 139th goal to overtake Edinson Cavani’s previous record.
Also on the scoresheet is the Argentine maestro Lionel Messi, while Vitinha also found the back of the net, leading to their nine-point lead at the top of the table.
Lens suffered a setback when Salis Abdul Samed was shown a straight red card in the 19th minute for a reckless tackle on Achraf Hakimi.
Mbappe's goal in the 31st minute made him PSG's all-time leading league scorer with 139 goals, surpassing Edinson Cavani's record. Vitinha added another goal just six minutes later with a powerful long-range shot, and Messi got in on the action with a tight-angle finish in the 40th minute.
Lens managed to pull one back through a penalty converted by Przemyslaw Frankowski in the second half, but it was not enough to overcome PSG's dominant performance.
The victory puts PSG in a commanding position at the top of Ligue 1, while Lens' title challenge took a hit with the defeat and the red card.