It was all too easy for Lyon. Thiago Mendes had time to ping a ball to the far post, which Sael Kumbedi dinked across the face of goal. Substitute Bradley Barcola sauntered to meet his pass, unmarked, and couldn't miss from six-yards out.
Three passes, and Paris Saint-Germain were beaten.
PSG would muster something resembling a fightback, but never found an equaliser. Lionel Messi was jeered every time he touched the ball. Kylian Mbappe tried to do far too much, spurning open passes and instead running into chunks of Lyon defenders. By the end of it all, Messi was making a swift beeline for the tunnel as the visitors celebrated a famous 1-0 win at Parc des Princes.
The loss was another disappointing result in a long line of poor performances from PSG this calendar year. They have lost five times in Ligue 1 since the turn of the year, as well as going out of the Champions League and the Coupe de France.
As such, they have gone from sure-fire league winners, up by 11 points over Marseille as recently as March 5, to nursing an increasingly precarious six-point lead, with some tricky fixtures still to come.
This has not been a bottling — not yet. But it very easily could become one. And for a side so superior in individual quality and spending power than the teams around them, a failure to win Ligue 1 would be PSG's biggest embarrassment yet.
Ironically, it might be PSG's biggest flaw as a side that will save them. Indeed, the Parisians have a poorly assembled squad, reliant on star power and hopeful that the pieces in between can keep everything intact.
That poor construction has hurt them repeatedly, with their front three's insistence on operating on a separate plane of responsibility seeing them suffer high-profile losses.
This time, though, the big hitters will need to show exactly why they were brought on. It is Messi and Mbappe, and not the nine poor souls who surround them, that are now required to respond.
