Paris Saint-Germain were brought back down to earth after their Champions League win over Real Madrid as they slumped to a 3-1 defeat at Nantes in Ligue 1 on Saturday.
Nantes, looking to qualify for Europe for the first time since playing in the 2004 Intertoto Cup, raced into a stunning 3-0 lead at the break -- the first time PSG had conceded three goals before half-time in over two years.
Neymar gave PSG hope with his first goal since last November, but then saw a poor 59th-minute spot-kick saved, reported AFP.
Mauricio Pochettino's men failed to put any further pressure on their opponents as they slipped to only a second league loss of the season.
But the capital giants remain 13 points clear of second-placed Marseille, who host Clermont on Sunday, at the top of the table.
It was a shock to the system for PSG after Kylian Mbappe's late winner on Tuesday gave them a 1-0 advantage in their Champions League last-16 tie against Real Madrid.
But Paris appeared more concerned with criticizing the referee rather than their own performance.
"We knew we were the team to beat.. The referee knows that, it's difficult, I don't want to judge, he's a person," PSG sporting director Leonardo told Canal+.
"The match was no longer controlled... It was completely out of control. You risk having players three months out with an injury, like Kylian."
Midfielder Marco Verratti claimed: "It's the only referee in the world who could do something like that. We had 10 yellow cards... Sometimes the referees have to take responsibility," he added even though six bookings were in fact handed out and not 10.
Nantes move into fifth place, only four points off the top three.
PSG coach Pochettino named all of Lionel Messi, Mbappe and Neymar in his starting XI for the first time in three months after the Brazilian's impressive return from injury as a substitute in the win over Real.
But Nantes wasted little time in taking a surprise lead with a wonderful counter-attack in the fourth minute, as Moses Simon played in Randal Kolo Muani to slip a fine finish through the legs of visiting goalkeeper Keylor Navas.
It was the third straight game that the forward has scored against PSG.
- Hit and miss from Neymar -
Messi was denied an equalizer shortly afterwards by an excellent save from Nantes 'keeper Alban Lafont, but PSG found themselves two behind with just over 15 minutes played.
Nantes became the first Ligue 1 club to score twice against the leaders since November, as Quentin Merlin unleashed a thunderous left-footed strike from outside the box into the top corner.
Nigeria winger Simon should have extended Nantes' advantage, but was denied by Navas when clean through on goal.
The hosts were left incensed when Dennis Appiah was sent off in the 44th minute for a tug on Mbappe near the corner of the area, but the decision was unsurprisingly overturned by VAR.
The referee was heading back to the pitchside monitor seconds later, this time to award a penalty to Nantes for handball against Georginio Wijnaldum.
Ludovic Blas stepped up to smash the ball down the middle and into the net.
But PSG got themselves back into the game less than two minutes after the restart, as Messi's glorious through ball found Neymar, who cut inside a defender and drilled the ball into the corner.
Kolo Muani wasted a brilliant chance to score his second just moments later, heading over from a corner when totally unmarked.
Despite their troubles at the other end, PSG remained a menace going forwards and Mbappe brought another good save from Lafont.
The away side blew another golden chance just before the hour mark, as Neymar tamely rolled a dreadful penalty straight into the grateful arms of Lafont.
PSG continued to dominate possession, but their chance of a fightback had gone as the Nantes defense and Lafont stood firm.
