After opening the scoring with a volley just five minutes in, the France international rounded off a fine display with another in the 84th minute to make it 5-0 to PSG.
Taking his tally up to four in the league this season to add to the 16 he netted with title holders Monaco, Mbappe has needed just 49 games to reach the milestone and has made 13 assists in that time. At 18 years and 10 months, Mbappe is the youngest to reach the tally in four decades.
1 - Kylian Mbappe is the youngest player to reach 20 goals in Ligue 1 in the last 40 years (18 years & 10 months). Crack. pic.twitter.com/hs2PXvlGVL— OptaJean (@OptaJean) November 4, 2017
It comes a few days after he set another goal record in the Champions League, becoming the first player under 20 to net eight times in the competition.
Mbappe has been breaking records since bursting onto the scene with Monaco in 2015-16 to become the most youthful debutant and goalscorer in the club's history, beating Thierry Henry's record.
Last season he became the youngest to net 13 Ligue 1 goals for 30 years and the youngest to score in a Champions League semi-final.