PSG, were without their star players like Neymar, Kylian Mbappe and Angel Di Maria - all tested positive for COVID-19.
Defending champions Paris Saint-Germain opened their Ligue 1 title defence with a shock 0-1 defeat against newly-promoted Lens.
The absence of some key players, including Neymar, Kylian Mbappe, Mauro Icardi, Andel Di Maria and Keylor Navas -- who have all tested positive for coronavirus, reduced Thomas Tuchel's choices for his starting line-up. As a result, several youngsters and new signings were brought into the squad to fill the places.
18-year-olds Kays Ruiz-Atil and Arnaud Kalimuendo made their first team debuts in attack while between the posts was guarded by 20-year-old Marcin Bulka, who was making just his second appearance.
Cameroon international Ignatius Ganago capitalised on a mistake from the unlucky Bulka in the 57th minute, when PSG's third-choice goalkeeper slid a weak pass towards Marci Verratti which was intercepted by Ganago and the former Nice striker calmly pulled the trigger to send the 3,800 home fans into ecstasy.
"I'm very happy. It feels good to open my account and I hope to score many more," said the 21-year-old Ganago, who arrived in Lens this summer.
"Even without Neymar or Mbappe, Paris have a very good team. We were solid, we were compact, we all worked together and it paid off in the end."
Before the game, PSG hadn't lost in Lens since 2009, and hadn't lost the opening game of a Ligue 1 season since 2011.
Tuchel's side dominated possession, 78.1 per cent to Lens' 21.9 per cent, but failed to create good chances as they recorded just one shot on target during the game.
"I don't think we could have done any better tonight," Tuchel told Canal, "I was happy with the first half we had. We controlled the game completely, and we had possession."
"We struggled to create scoring chances today. No opportunities? Yes, I agree. But we have a small group, and we are missing the players who make the difference."
The pressure for the German coach and his PSG team may grow in the coming week as they face a busy schedule with a clash against last season's runners-up Marseille on Sunday and followed by Metz at the Parc des Princes on Wednesday.
