Marseille and Lille cancelled each other out, 1-1, at the Velodrome.
Marseille remained second, on goal difference, when third-place Monaco drew 0-0 at Reims in the late game. The pair are four points behind PSG, who play in-form Lyon on Sunday, and three ahead of Lille.
Lens moved up to sixth after coming from behind twice to draw 2-2 at Auxerre.
In Marseille, Quentin Merlin gave the home team a 17th-minute lead but Bafode Diakite levelled for the visitors.
Both coaches were inclined to say their glasses were half full.
"I think we played a great game against a great team." said Marseille's Roberto De Zerbi. "Our chances came from the quality of our play, theirs from our mistakes."
De Zerbi said his team should have won. So did Lille coach Bruno Genesio.
"I have mixed feelings. I'm pleased to have come back from a goal down but a little frustrated because we could have done better and we deserved better," said Genesio.
"We've played 25 games, we're fourth, we're unbeaten in 16 and we've qualified for at least the last 16 of the Champions League," he added.
De Zerbi was equally bullish.
"We're second, with 30 points from 15 games, and that's no mean feat."
He compared his team to their last two home opponents, who are also their closest rivals in the table.
"We're still a work in progress," he said. "Lille and Monaco are teams that have been building for several years."
"We've revolutionised everything. The big difference between us and Lille or Monaco is awareness and knowledge of their game and their players. It takes a little time."
Monaco coach Adi Huetter struck a similar note after his team's goalless draw.
"We missed out on two points and a great opportunity to move up to second place, so we're not happy," said the Austrian.
But, he said, "We're on the right track."
Saint-Etienne, in 16th, lost 2-1 at Toulouse on Friday and axed coach Olivier Dall'Oglio on Saturday, Training centre director Laurent Huard has taken over "until further notice"
Dall'Oglio is the third coach to be relieved of his duties in Ligue 1 this season, after Michel Der Zakarian at Montpellier and Julien Stephan at Rennes.
