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: Lille was the better side by chances too.
Lille: +3.9 for the season (4 in the table). Troyes: +0.1 (16). The gap between points and xPTS is built from matches like this one.