PSG has not tasted defeat in Ligue 1 since the opening match of the season, but manager Antoine Kombouare remains under pressure to produce results.
PSG suffered a surprise defeat to Lorient at home in the first week, but since the club has gone 12 league games without a defeat, with nine of those wins.
After an offseason spending spree of more than $100 million, it's not much of a surprise PSG has done so well as it searches for its first title since 1994.
But now that it sits atop the standings after 13 games, it's under pressure to remain at the top.
"We must retain that spot," PSG sporting director Leonardo told L'Equipe.
PSG's offseason additions, including Javier Pastore, have made a giant impact, but Kombouare has little room for error with new investors eyeing a more high- profile coach to guide the awakening French giant.
The Paris club's unbeaten streak is their longest since a run of 17 games from September of 2003 to March 2004 and it has resulted in a three-point lead over Montpellier, while main title challengers Lille and Lyon are six and seven off the pace.
Lyon hosts Rennes on Friday to open the weekend's matches, while Lille visits Toulouse on Friday as both clubs will get a little rest before their Champions League matches next week.
When PSG plays Nancy on Sunday at the Parc des Princes, it will know if either side has closed the deficit, as well as second-place Montpellier, which hosts Marseille on Saturday.
With the best home mark in France, PSG has won its last six at home since the shock loss to Lorient, the expectation is to secure three points this weekend. Nancy, meanwhile, has just one point on the road so far this season.
However, PSG has won just one of the last five home matches with Nancy, with a tie being the final result in the other four. Nancy actually has won more than PSG in Paris in the series, but not since 1999.
Nancy midfielder Reynald Lemaitre said his club's aim is to pick up points, no matter who the opponent might be.
"We're not going to Paris as victims, even if a defeat would be a logical result," Lemaitre said. "Even if we've climbed a bit up the table we're still in the relegation zone and we really need to pick up points, no matter the quality of our opponents."
PSG will be without suspended midfielder Jeremy Menez and Mohamed Sissoko, but French international Blaise Matuidi is set to return from six weeks out with a thigh injury.
Kevin Gameiro has not scored in his last seven appearances in all competitions but is still tied atop the scoring charts with eight goals this season and PSG has scored in every game since the opening week loss.
Nancy will be without the services of Daniel Niculae, who scored game-winning goals against Brest and Nice, due to a groin injury, but coach Jean Fernandez knows the pressure is on PSG and Kombouare, even if it isn't warranted.
"People say PSG aren't playing well. He's certainly got quality players but you cannot build a side by simply waving a magic wand. You have to give the coach time and show some patience," Fernandez said.
Unfortunately for Kombouare, dropping points against Nancy isn't an option, as his job is likely on the line with each passing game. And a loss to Nancy will start more speculation about a coaching change.
Former Chelsea manager Carlo Ancelotti has been rumored as a replacement, and a slip up against Nancy might be all the club owners need to make a change.
Also Saturday, Rene Marsiglia debuts as coach as Nice hosts St Etienne, Dijon hosts Bordeaux, Evian hosts Lorient, and Ajaccio hosts Caen. On Sunday, Brest hosts Sochaux and Valenciennes hosts Auxerre.