Newly-promoted Reims has shaken off the rust from a long absence from Ligue 1 with four wins and two draws during its last six games, and will try to surprise unbeaten PSG on Saturday.
Back in the top flight in France for the first time in over 30 years, Reims is fifth in the standings while fellow promoted sides Bastia and Troyes are stuck in the bottom half.
Reims started the season with consecutive defeats, but has won all four of its home matches since and also tied Toulouse and St. Etienne on the road.
Manager Hubert Fournier actually believed the international break was bad, and hoped his club could return to form at the Parc des Princes this weekend.
"We've played eight very tough games and now we have to stop," Fournier said. "We're trying to keep up our focus because otherwise it'll be very, very difficult for us at the Parc des Princes."
PSG is the class of Ligue 1, undefeated in eight matches this season with four wins and four draws. Although Marseille leads the table with 19 points, three more than PSG, the Paris side is the favorite to win the title.
Fueled by another offseason of massive spending, PSG has fortified an already incredible lineup. The biggest addition of the summer was Zlatan Ibrahimovic, who leads the league with nine goals.
Reims does not measure up name-wise with PSG, but its performances have proven it could give the favorites trouble this weekend.
"It's going to be a tricky game. We'll do everything we can to try and win, we're at home. Reims want to play, though, want to show what they can do in Ligue 1," PSG striker Kevin Gameiro said.
"It's always difficult to play these kinds of teams as they're very focused."
Reims are just five points off the top, and a win over PSG would put the squad in position to challenge for a European place this season. But reality could also set in this weekend, and leave a lot of work ahead.
Unbeaten Lorient also plays Saturday, as it visits Valenciennes in a top-half clash. Defending champion Montpellier visits Rennes on Saturday, when it will try to turn around a poor start to the season which has seen the team get just eight points from eight matches.
Also Saturday, Nancy will try to end a six-fixture losing streak when it hosts Sochaux, Evian hosts one-loss Toulouse, and Nice hosts St Etienne.
On Sunday, Marseille will try to snap a two-match skid when it visits promoted Troyes, which is winless in eight matches this season. Marseille started with six straight wins, but lost to Valenciennes and then tied PSG.
Ajaccio hosts Bastia in a battle of three-win squads and third-place Lyon will try to end a three-game winless streak when it hosts Brest in the other Sunday matches.
On Friday, Marko Basa scored three minutes into stoppage time as Lille secured a 1-1 draw at Bordeaux. Ludovic Obraniak scored in the 18th minute as Bordeaux grabbed an early lead, but Basa rescued a point at the death for Lille.
Bordeaux remained unbeaten, but has six draws and three wins. Lille earned its fifth draw against two wins and two losses this season.