Paris Saint-Germain have needed a late goal from defender Danilo Pereira to scrape a 2-1 win at Lorient and restore their five-point lead at the top of the French league.
Pereira headed home Neymar's corner in the 81st minute as unbeaten PSG maintained their gap over second-place Lens.
"We were sloppy technically," coach Christophe Galtier said.
"We looked rattled in the second half."
Lionel Messi was rested for Sunday's game because of some inflammation in his Achilles tendon. The Argentina star, who will look to win the World Cup for the first time in his stellar career, is expected to resume training next week.
Galtier thinks some of his players may have been holding back against Lorient for fear of getting injured so close to the tournament, as happened to Germany's Timo Werner.
"It gets inside the players' minds when they hear that such and such is injured, and won't play at the World Cup," Galtier said.
"Certain players held back a bit, were a little bit worried about tackling."
Messi was replaced in attack by 20-year-old Hugo Ekitike, who marked a rare start by setting up Neymar's opening goal after nine minutes. Neymar's 11th league goal moved him level with Kylian Mbappe atop the scoring charts.
Lorient equalised in the 53rd through club top-scorer Terem Moffi's ninth of the campaign.
Moffi hit the crossbar shortly after as Lorient got on top, but then failed to pick up Pereira from Neymar's corner.
Elsewhere in Ligue 1, third-place Rennes drew 1-1 at Lille to fall five points behind Lens.
The home side led through 38-year-old defender Jose Fonte's early goal, but midfielder Benjamin Bourigeaud levelled for Rennes with a penalty in the 58th.
Rennes are only one point ahead of fourth-place Marseille, who beat Lyon 1-0 at home for a first win in five league games.
Chile striker Alexis Sanchez twice went close for Marseille before central defender Samuel Gigot headed in from a corner just before halftime.
Fifth-place Monaco won 2-0 at Toulouse, with goals from midfielder Aleksandr Golovin and forward Breel Embolo.
Elsewhere, Nice beat Brest 1-0, Reims won by the same scoreline at home to Nantes and Clermont drew 1-1 with Montpellier.