Paris Saint-Germain went top of the Ligue 1 table with a thrilling 4-2 victory away to Brest. The result leaves the hosts twelfth in the table, while Anger and Clermont Foot can shuffle PSG off of their perch with wins.Paris Saint-Germain dominated the opening exchanges and underlined their superiority in the 23rd minute as Ander Herrera volleyed home the opener. Kylian Mbappe doubled the lead with an opportunistic header in the 36th minute after having started the move himself.Brest were not passive opponents though, and clawed their way back into the match with a well worked goal. Romain Faivre's delicious backheel allowed Franck Honorat space in the box to arrow a shot past Keylor Navas into the bottom corner, making it 2-1 going into the break.Keylor Navas pulled off a huge save from Irving Cardona in the 67th minute, after which Idrissa Gana Gueye made it 3-1 with a howziter from range. Navas continued his superb form, making another save in the 77th minute from what looked a certain goal.Idrissa Gueye has scored in Ligue 1 for the first time since December 2020, when he struck for PSG against Strasbourg.Rare occurrence. 😁 pic.twitter.com/6rQjctsfCB— Squawka Football (@Squawka) August 20, 2021Brest was not done, though, and Steve Mounie made it 3-2 in the 85th minute with a supreme piece of control and finish. As the hosts pushed up in search of an equalizer, PSG took advantage with Angel di Maria scoring with a lob over the keeper at the end of a counter-attack in injury time to make it 4-2.Here are five talking points from the game:#1 PSG's defence is an absolute messKimpembe had a night to forgetFor all the excitement over Paris Saint-Germain's recruitment of Lionel Messi, it's perhaps their acquisition of Sergio Ramos and Achraf Hakimi that may come to benefit them more. Even without the likes of Neymar and Messi, PSG had no trouble conjuring up goals against Brest. However, it was an absolute defensive nightmare of a performance.Indeed, despite shipping in two goals, one could make the case that Keylor Navas was one of PSG's best performers on the night. The Costa Rican keeper pulled off a couple of stunning saves at crucial moments in the game, where conceding would've had catastrophic consequences for PSG.Presnel Kimpembe and Abdou Diallo were often caught unawares, with most of Brest's attacks and goals coming down their right wing. Mauricio Pochettino has a huge task of shoring up this defense on his hands, having conceded five goals in three games so far.FT Brest 2-4 PSGThird straight match in which PSG could very easily have ended up with a draw and their opponents would have deserved it. Third straight match in which PSG's individual talent sees them through. Forget Messi - Hakimi again looking like the signing PSG needed.— Jeremy Smith (@jeremysmith98) August 20, 2021#2 Brest can surprise quite a few teams this seasonSteve Mounie was a thorn in PSG's side tonightMichel Der Zakarian is quite the experienced coach when it comes to French football and what he has seen from his side in their opening three games ought to fill him with pride.Brest narrowly escaped relegation last season by a single point, with many tipping them to be favorites to go down this time around. However, they have been anything but league fodder, pulling off impressive draws against Rennes and Lyon coming into this game.It would not be a stretch to say Brest deserved a point from the game at the very least. The defensive low block held PSG at bay for large stretches, while the counter-attack was often swift and decisive. Brest looks like a team that's a sum of their parts and could very well stay in the league this season, if not more.