The Brazilian sulked his way off the pitch, kicking a loose ball in frustration after seeing two yellow cards within 90 seconds. It was a sobering end to an electric 62 minutes from Neymar.
All neat flicks and darting dribbles, he had controlled the match before throwing the result into jeopardy by picking up an unnecessary second booking for a dive in the Strasbourg penalty area.
It was a moment not out of character for the oft-criticised forward. Neymar has long been maligned for his short temper and penchant for going to ground. But this time, it could have cost his team dearly.
The Brazilian is lucky, then, that his side have match winners elsewhere. In the 94th minute, Mbappe burst into the box before being dragged down. The referee swiftly pointed to the spot, and the Frenchman tucked his go-ahead penalty past a sprawling goalkeeper to give the Ligue 1 leaders a 2-1 win over the 19th-placed side.
In the end, then, Mbappe was the difference. But for a PSG side expected to demolish teams of Strasbourg's calibre, the Neymar incident is probably what will be remembered most.