Marseille's perfect start to the Ligue 1 season came to a grinding halt this afternoon as they were trounced at Valenciennes.
The hosts raced into a 2-0 lead in the first half through Gael Danic and Anthony Le Tallec before Marseille's dismal afternoon took a further nosedive when goalkeeper Steve Mandanda inexplicably rolled the ball out to VA's Foued Kadir, who had a simple task to fire home.
Le Tallec added his second after the break before Jordan Ayew bagged a late consolation for the beleaguered visitors.
The defeat ends a run of six straight wins at the start of the season for OM, who could see their lead at the summit trimmed to a point if Lyon defeat Bordeaux tonight.
VA, meanwhile, move comfortably into the top half of the standings after their third win of the season.
The hosts wasted little time in going ahead, 16 minutes on the watch when Danic curled home a wonderful free-kick from 20 yards into the top-right corner.
Valenciennes doubled their advantage on 34 minutes when Danic dispossessed Rod Fanni, surged into the area and teed up Le Tallec for a simple finish.
And the lead was out to three in the 39th minute as a moment of madness by Mandanda cost his team dear.
There looked to be no danger for the visitors as the goalkeeper gathered the ball, but for reasons known only to himself he threw out straight to the disbelieving Kadir, who duly slotted home.
Mandanda made partial amends with a good save to deny Le Tallec on the hour, but within three minutes VA had their fourth, Kadir delivering a perfect cross from the left for Le Tallec to head home.
A small crumb of comfort went Marseille's way in injury time when Ayew lashed home on the volley to deny Nicolas Penneteau a clean sheet, but it was too little to mask an abject performance by the league pacesetters.