Paris Saint-Germain lost more ground to surprise Ligue 1 leaders and fierce rivals Marseille after being held to a 1-1 draw by Monaco in Paris Sunday, their sixth draw in nine French league games.

Perhaps still recovering from their mid-week Champions League win over Barcelona, PSG looked tired from the off, while the continued absence of star striker Zlatan Ibrahimovic through injury was far more noticeable than it had been against the Catalans.

Nevertheless, they looked on course for victory when Lucas’s 70th-minute strike found the back of the net, only for Monaco’s substitute striker Anthony Martial to thump home a close-range equalizer deep into injury time.

The draw prevented PSG from leaping into second place behind leaders Marseille, who had notched their seventh consecutive victory on Saturday, 2-1 away to Caen, and are now seven points clear of their Paris rivals.

The first half was uneventful until Maxwell's cross on 37 minutes went begging as a sluggish Edinson Cavani arrived slightly late for a simple nod in.

PSG were left to thank Salvatore Sirigu's reflexes after he then finger-tipped a Yannick Ferreira Carrasco snap-shot onto the crossbar on 43 minutes to hold the score to 0-0 at half-time.

PSG centre backs Zoumana Camara and Luiz were kept busy after the break, but were never panicked by the Monaco forward line.

The home side almost scored when Javier Pastore put Cavani in just before the hour with a deft through ball, only to see the Uruguayan run through with perfect timing and miss the ball completely.

Monaco came close to grabbing a goal moments later when Andrea Raggi thought he'd scored only for Gregory Van Der Weil appearing from nowhere to clear off the line with Sirugu on the floor.

But then the deadlock was finally broken, an unmarked Moura latching on to a right-wing cross from substitute Jean-Christophe Bahebeck which he sent to the far post with a sharp volley that gave keeper Danijel Subasic no chance.

PSG failed to hold one, however, with Luiz’s fluffed clearance seeing the ball fall to Martial, unmarked, in the box. The substitute made no mistake with his finish to salvage a point for Monaco.

“We didn’t do what was required to win 1-0, my team was a bit shaky,” PSG coach Laurent Blanc said after the match. “Marseille deserves to top the table, but don’t forget they are not in the Champions League.”

Marseille lead Ligue 1 with 22 points, five more than Bordeaux in second, with unbeaten PSG third on 15, ahead of Lille and Nantes on goal difference.