The score says how it ended. xG says how it should have ended: it is the sum of the chances each shot was worth, not an opinion about the game.
The score matched the game: Paris FC was the better side by chances too.
Marseille: −2.3 for the season (17 in the table). Paris FC: −0.1 (3). The gap between points and xPTS is built from matches like this one.