PSG dent Monaco's title hopes
Lyon's victory on Saturday had put them three points ahead of Monaco, while Marseille had gone above them into second courtesy of a win over Bastia.
With the pressure on, Didier Deschamps's side knew that a win in Paris would get them back on terms with Lyon at the top of the table.
The Principality side got in front at Parc des Princes six minutes before the break when prolific marksman Shabani Nonda fired in to keep their title dreams alive.
However, PSG came back after the interval, and Fabrice Fiorese drew the sides level on 58 minutes before Brazilian superstar Ronaldinho broke Monaco hearts with a 76th minute penalty.
The result keeps PSG's hopes of a European place alive but is a body blow to Monaco's title aspirations.
Monaco have just three games left in the championship race to claw back the three-point deficit on Lyon, while they must also make up a point on Marseille if they want to bring the title back to Stade Louis II.
Match summary:
PSG 2-1 Monaco
Click here for Le Championnat league table.