Tuchel's side dominated possession, 78.1% to Lens' 21.9%, but failed to create good chances as they recorded just one shot on target during the game.
The Bayern defeat led to new elections for club President being called for March, Ronaldo Koeman replacing Quique Setien as coach, the start of a mass dressing room clear-out and Leo Messi saying he wanted to leave.
Nathan Ake has been brought in to give more options at the back, but Guardiola's plans have been somewhat frustrated by new Spain international Eric Garcia's refusal to sign a new contract, and he could be Barcelona bound, while John Stones and Nicolas Otamendi are not reliable enough over a long season.
Messi received a one-match ban for an altercation with Chile's Gary Medel in the Copa America third-place playoff in July last year, which Argentina won 2-1.
"Neymar told me that it was a racist insult. I didn't hear anything on the field," PSG coach Thomas Tuchel said. "Racism in life, in all domains, in sport, should not exist."
The 2021 edition of the championships will be held in Turin, Italy. Enditem
There has also been increased government support to athletics. For instance the government, despite a COVID-19 lockdown, facilitated the travel of a team of athletes, headed by Cheptegei, to travel to Monaco for the Diamond League.
Marcos Llorente impressed for Atletico last season and Diego Costa showed signs of life, but the club needs record signing Joao Felix to step forward and show why they paid 120 million euros for him a year ago.
The French defending champions kicked off their league title defence on Thursday with a shock 1-0 defeat at newly-promoted Lens, in a game which a shorthanded Tuchel had to field several young players such as 18-year-old league debutants Kays Ruiz-Atil and Arnaud Kalimuendo and 20-year-old goalkeeper Marcin Bulka, who was just making his second appearance for the first team. Enditem
The other three players are Argentine duo Angel Di Maria and Leandro Paredes, and goalkeeper Keylor Navas.
The 37-year-old veteran's penalty helped Ever Bright take the lead in the 42nd minute.