Lens, who sit second bottom, are nine points adrift of safety while champions PSG are just a point behind leaders Lyon.
The visitors will be fresher after PSG were played on Wednesday in the Coupe de France.
But Laurent Blanc's men lifted morale after a goalless Ligue 1 draw against Monaco on Saturday by beating the same opponents 2-0 at the Parc des Princes.
Goals from David Luiz and Edinson Cavani were enough to send PSG through to the competition's semi-finals, keeping alive ambitious hopes of a quadruple trophy haul this term.
PSG have already qualified for the Coupe de la Ligue final and go to Chelsea next week for the second leg of a last 16 UEFA Champions League tie that is evenly poised at 1-1.
"I think we played two very good games against Monaco," the Brazil defender told the club's official website.
"The difference was that we scored early [on Wednesday].
"We are playing well and we are getting close to the key moment of the season.
"Now is the time to start winning titles together."
PSG have not had it all their own way in Ligue 1 this season, drawing a league-high 11 matches.
And although they are firmly embroiled in a three-way race for the title, alongside Lyon and Marseille, their ongoing involvement in cup competitions means they can ill-afford a slip-up against Lens.
PSG have won just one of their last four league games but Lens are without a win in any competition in 2015. Their last victory was a 2-0 success against Nice on December 19.
Also in PSG's favour is their recent record against Lens, which sees them unbeaten in 10.
Since Lens' 3-1 triumph in Paris in November 2006, PSG have won six of 10 meetings in all competitions.
That includes a 3-1 win at Lens in October of this season, a fiery match which saw three players sent off.
Cavani was infamously dismissed for his 'sniper' celebration following a 55th-minute penalty in the match.
The Uruguayan forward was booked for the celebration and received a second yellow card for his protestations. Jean-Philippe Gbamin and Jerome Le Moigne were sent off for the hosts.
