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: Juventus was the better side by chances too.
Juventus: −2.1 for the season (7 in the table). Parma: +0.6 (15). The gap between points and xPTS is built from matches like this one.