So far PSG have won all three of their games and in an impressive fashion as well so it will be difficult for Brest to get something out of this. Of their last three games, it's only one win they have to boast of and sitting in 12th place doesn't help their case either. I see this game going a bit one way and that is in the favor of PSG because Luis Enrique's men will be looking to continue in their sterling ways, adapting well to life without Mbappe and I do not see Brestois being a problem, or maybe they can if they play their cards right since in football anything can happen.
Anything can definitely happen in football and in the case of Brest they can also show some level of talent in their game and stand a worthy opponent against PSG. They have not done too well in this season after just winning one match and playing with a team that has 100% record so far in the league, it is very likely that they will not win this game because PSG has the best squad and the best experience in this game, so they don’t need to feel threatened by playing against them in the league. Brest can try not to lose too many games so that they don’t go in relegation but in the case of playing with PSG, they can’t be so sure of even finishing the match with a draw.
Brest finished third in the table last season with seven games lost, seven games draw and twenty games won, talking about Brest relegation is actually too early because the only lost two matches first and second they won the third one with 4-0 against saint Etienne although saint Etienne just came back from the relegation after been absent for two consecutive seasons, Brest winning against saint Etienne is a sign that they are ready to compete for the top three positions, regarding their match against PSG, if eventually they lost I will not mount blame on them because PSG is the strongest team in Ligue 1 who have won all their matches.
The league standings can change every match because teams don't know what each other's capabilities are in their first match. You are right that anything can happen in football. A team that plays good defense can score a goal with a counterattack and finish the match with this score, even if they don't have star players.
I wonder what Brest will do against PSG because even though PSG won, they still can't play the game they want. PSG is above the other teams in terms of player quality, but that doesn't mean they will win every match comfortably. We may see unexpected scores in the league.