The 23-year-old star had a shaky start to the match and missed a penalty in the 23rd minute. However, Neymar did better, slotting home his penalty in the closing stages of the first half, which combined with an earlier own goal meant the home side went into the break with a 2-0 lead.
The Brazilian then increased it to 3-0 early in the second before the visitors managed to reduce via Wahib Khazri. Then Mbappé – who missed the first leg through injury – scored the first goal of the season with just under 70 minutes played and new signing Renato Sanches made it 5-1 just before full-time.
Defender Enzo Tchato spruced up the final score for Montpellier a bit when he finished off the scoring in the 91st minute.
Lionel Messi left the field scoreless.
The win means that PSG now has a full pot after two games played.