The highly-rated forward netted twice as the Ligue 1 side downed Dortmund 3-2 in the first leg of their quarter-final clash, putting Leonardo Jardim's men in pole position to reach the last four.
And, in doing so, Mbappe became the youngest player to score twice in a Champions League knockout fixture at the age of 18 years and 113 days old.
2 - Kylian Mbappé is the youngest player to score two goals in a Champions League knockout game (18 years, 113 days). Brilliant.— OptaJohan (@OptaJohan) April 12, 2017
Mbappe has now scored 21 goals in all competitions for Monaco so far this season following his Dortmund double, with two of those strikes helping see off Manchester City in the Champions League last 16.
2 - Mbappé (18 yo & 3 months) is the 2nd youngest player to score in the 1/4 final of the CL, after Bojan in 2008 (17 yo & 7 months). Early.— OptaJean (@OptaJean) April 12, 2017
He also became the first player since City's Leroy Sane to score on his first three knockout stage appearances in the Champions League against Dortmund, in what was a memorable night for him.
Only Stoke City loanee Bojan, formerly of Barcelona, has netted in a Champions League quarter-final tie at a younger age (17 years and seven months old) than Mbappe as well.