Paris Saint-Germain were held to a 1-1 Ligue 1 draw at Saint-Etienne in new coach Mauricio Pochettino's first game in charge on Wednesday as the French champions failed to make their ball possession count.
"It was a difficult game. We need to keep working. I'm not looking for excuses, we need to improve the way we play and to improve our performances," said Pochettino.
"We are PSG, we must win. I arrived three days ago but I'm happy with the way the players tried to apply what we worked on during practice."
Four days after being named as successor to Thomas Tuchel, who led the club to their first Champions League final last August, Pochettino was left contemplating the task at hand following PSG's lacklustre performance at Geoffroy Guichard.
Saint Etienne took the lead in the 19th minute when Hamouma fired home after Idrissa Gueye had been dispossessed in front of the area.
PSG enjoyed nearly 70% of possession, but in the absence of Neymar, still recovering from an ankle injury, lacked stamina and inspiration while Mbappe had yet another match to forget.
Verratti, positioned high up on the pitch as a playmaker, was decisive on PSG's goal but the Italy midfielder was otherwise as uninspired as the rest of the team in a disappointing performance by the French champions.
Elsewhere, former France coach Raymond Domenech returned to the bench with Nantes, 10 years after Les Bleus were knocked out of the 2010 World Cup first round in embarrassing fashion, with the Canaries held to a 0-0 home draw against fourth-placed Stade Rennes.