Didier Deschamps' men embarrassed their great rival with a thumping win in Provence, meaning PSG is knocked off Ligue 1's summit.
Loic Remy opened the scoring with a fine header, but the first half was a tight affair. After the break, OM extended the lead as Morgan Amalfitano was the benefactor of loose play in PSG’s midfield, driving a fine second goal for the home side. Five minutes from time, Didier Deschamps’ side added a third, with Andre Ayew heading home.
Marseille watched PSG dominate possession in the early throes, but proved to be more efficient in front of goal, scoring with its first meaningful attack. Cesar Azpilicueta was allowed to attack down the right, and his center from deep was headed superbly into the net from the penalty spot by Remy.
While the game thereafter was played with tremendous passion, it was the defensive units of both sides which were enjoying the best of the match. Opportunities of genuine note were rare, yet Mohamed Sissoko nearly scored out of the blue with a long range drive that came off the inside of Steve Mandanda’s post.
After a rather tense first half, the beginning of the second period was a good deal more open, with efforts at either end of the park threatening.
Azpilicueta got forward effectively once more, but as Lucho Gonzalez closed in on a potential second for OM, Diego Lugano did just enough to put the Argentine off. Three minutes later a terrific charge into the PSG box by substitute Jordan Ayew – on for the injured Remy – saw him power by several challenges before being stopped in a physical manner, though referee Lionel Jaffredo waved away penalty claims.
PSG was not so impressive, however. Jeremy Menez found a rare yard of space inside the home box, but his shot was high as Steve Mandanda went untested all evening.
Antoine Kombouare tried to change things, replacing Kevin Gameiro and Javier Pastore with Mevlut Erding and Mathieu Bodmer, but no sooner had this decision been made as Marseille had doubled the lead.
Slack play in the center of the field saw Blaise Matuidi cough up possession to Jordan Ayew, who released Amalfitano to drive low into the net.
There was no response from the guests, and Marseille would add to PSG's misery with five minutes remaining. Amalfitano supplied the ammunition, delivering for Andre Ayew to head past Salvatore Sirigu with the help of a deflection.
Such a heavy loss throws Kombouare’s position at the head of PSG into doubt, particularly as les Parisiens have now fallen three points behind shock league leader Montpellier. While victory in such a crucial fixture has boosted Marseille’s morale, the club remains nine points back of its great rival in the title race.