Having started the game tied for the record with Zlatan Ibrahimovic on 113 goals, the Uruguay forward moved clear of his former team-mate when he converted a 75th-minute penalty at the Parc des Princes.
Cavani went on to add another to his tally before the final whistle too, heading home Thomas Meunier's cross to draw the runaway champions level.
His second-half brace made sure PSG avoided suffering a first home defeat in the league this season, as they recovered from a 2-0 down to pick up a point in the French capital.
Cavani surpassed Swede Ibrahimovic's overall total of 157 goals for the big-spending club back in January, with his
With his double against Guingamp, Cavani has scored 38 goals in all competitions this season.