Despite taking an early lead through Adamo Coulibaly, Lens self-destructed as they conceded three goals in 27 minutes and had two players sent off in front of a packed house at the national stadium, just outside of Paris.
PSG had Edinson Cavani red-carded.
Yohan Cabaye, Brazilian Maxwell and under-fire Uruguayan Cavani, from the penalty spot, did the damage for Laurent Blanc’s side as they went second in the table, one point ahead of Bordeaux.
Marseille can extend their advantage when they host Toulouse on Sunday while Bordeaux await fourth-from-bottom Normandy club Caen later the same day.
Lens remain third from bottom with just eight points from 10 matches.
“The match was a bit bizarre,” said PSG ‘keeper Salvatore Sirigu.
“We started well and then conceded a goal but we had the force to bounce back and the desire to win and that will make us stronger.
“Things are a bit complicated at the moment with all our injuries but we’re working to return to full strength,” added the Italian.
Lens took the lead against the run of play with only 10 minutes gone when 33-year-old Coulibaly intercepted a loose ball just inside the PSG half and raced towards goal.
An angled shot from the left of the box took a telling deflection off the unfortunate stand-in captain Thiago Motta and beat Sirigu at the far post to put Lens in front.
PSG, despite playing in Paris and without injured talisman Zlatan Ibrahimovic, were the away side, and struck back decisively with two goals in six minutes that swung the match back in their favour.
Former Newcastle favourite Cabaye took advantage of a rare chance to be included in the starting eleven, as he pounced on a loose ball 25 yards from goal and drove home the equaliser that Rudy Riou failed to keep out on 28 minutes.
Six minutes later, the Lens ‘keeper was badly at fault as a miscued clearance fell to defender Maxwell 35 yards from goal and his instinctive shot towards goal looped over the defence and Riou and into the goal which handed the initiative back to Blanc’s men.
Lens coach Antoine Kombouare, who was in charge at PSG between 2009 and 2011 and is a former player with the capital club, then saw his side’s fortunes take a decisive turn for the worse eight minutes into the second half when Jean-Philippe Gbamin gave away a penalty and was sent-off in the process.
Although he made light contact with Cavani who was in a goal-scoring position, a penalty and subsequent red card was harsh on the promoted northerners.
Cavani, who has come in for sustained criticism in the French press over his lack of fire-power in front of goal, converted the penalty before being comically sent off during his celebrations.
Firstly handed a yellow for a harmless gesture towards the crowd, he then grabbed the referee’s arm in protest which prompted a straight red from the harassed official Nicolas Rainville.
“I don’t know why Cavani was sent-off, players should be allowed to ask for an explanation and it was done in a polite way but it’s just not possible that this can happen. It’s a shame for the fans and the spectacle,” continued Sirigu.
Moments later, Jerome Le Moigne was given his marching orders for Lens for a second bookable offence as the home side went down to nine men and they never recovered.
PSG can now look forward to their next Champions League fixture on Tuesday when they travel to Cyprus and a key match against APOEL Nicosia- AFP