Dimitri Payet's second-half free kick was enough to give French league leader Saint-Etienne a 1-0 away win at Lyon on Saturday and intensify the pressure on beleaguered Lyon coach Claude Puel.
The 100th local derby between the fierce rivals was settled by another moment of magic from Payet, who has made a stunning start to the season with seven league goals in as many games to give Saint-Etienne bragging rights over Lyon after 15 years of misery.
Saint-Etienne proudly tops the league for the first time since 1982 - during Michel Platini's heyday - with 16 points, while Lyon's fall from grace means it is second-to-last after securing seven straight titles from 2002-08.
"It's a serious situation, a grave situation," Lyon president Jean-Michel Aulas said. "It's unfair because we deserved to win the match."
Aulas gave his backing to Puel, however, saying there would be no immediate decision on his future.
Saint-Etienne coach Christophe Galtier was generous in his praise of Lyon and modestly played down his team's good start.
"We're a modest bunch, because we know how far we've come in the past two seasons," Galtier said. "We didn't deserve to win, at no point in the match did I think we would win."
When Saint-Etienne was awarded a free kick some 25 meters (yards) out on the right side of the penalty area in the 75th minute, Payet curled it brilliantly into the top right corner, with France goalkeeper Hugo Lloris unable to keep it out.
However, TV replays showed Lyon midfielder Kim Kallstrom clearly won the ball cleanly when tacking Loic Perrin and that there was no foul.
"The foul by Kim Kallstrom does not exist, and it's that free kick which led to the goal," Aulas said.
Aulas angrily remonstrated with referee Antony Gautier in the corridor after the match, repeating over and over that there was no foul and imploring Gautier to study the replays.
"I know what the Lyon bench is like, they put a lot of pressure on the officials," Galtier said.
Moments before Payet's goal, former Saint-Etienne striker Bafetimbi Gomis thought he had given Lyon the lead, only for his effort to be ruled out for offside. Gomis hit the post with a firm downward header early in the match at Stade Gerland.
Shortly after Payet's goal, Kallstrom went close with a long shot.
The defeat may spell the end for Puel, with French media speculating this week that a defeat would lead to his sacking after little more than two years in charge.
Reports this week said several key players no longer want to play under Puel, who was known as a strict disciplinarian.
Following Lyon's fourth defeat of the season, Aulas dampened any speculation about Puel possibly being fired.
Asked if Puel would be fired in the days to come, Aulas replied, "No, not at all."
Unbeaten Rennes won 2-1 away at Nice and was in second place with 15 points, one behind Saint-Etienne. Toulouse has played a game less and was in third place with 13.
Rennes has yet to lose after seven rounds, and took the lead in the seventh minute through midfielder Stephane Dalmat, before striker Danijel Ljuboja equalized in the 26th with his first goal for Nice.
Striker Victor Hugo Montano's third league goal of the season gave Rennes the win in the 77th.
Defending champion Marseille beat Sochaux 2-1 at home with goals from defender Taye Taiwo and midfielder Lucho Gonzalez.
At Stade Velodrome, winger Andre Ayew set up Taiwo for a shooting chance from 25 meters and the defender's strike flew into the net to give Marseille the lead in the 19th.
Gonzalez made it 2-0 in the 61st when he ran onto a deft headed pass from Loic Remy and hit a quick shot past goalkeeper Matthieu Dreyer.
Midfielder Nicolas Maurice-Belay grabbed a consolation goal for Sochaux.
Striker Olivier Giroud put Montpellier ahead against last-placed Arles in the 41st after collecting a pass from Romain Pitau and finishing confidently.
Giroud added another from the penalty spot early in the second half, before Yann Kermorgant pulled one back for Arles.
Souleymane Camara wrapped up Montpellier's win when he got his first goal of the season with 10 minutes remaining.
Kevin Gameiro scored after just four minutes for Lorient, but Monaco forward Dieumerci Mbokani leveled in the 24th.
Monaco center half Sebastien Puygrenier was sent off just before the interval, but Lorient struggled to make the most of the extra man until Lynel Kitambala scored the winner in the last minute.
Auxerre remains near the bottom after throwing away a 2-0 lead.
Auxerre was without striker Anthony Le Tallec through injury but the former Liverpool forward was not missed as forward Dennis Oliech scored twice after just 11 minutes.
Alexandre Cuvillier pulled a goal back soon after for Nancy and striker Marama Vahirua made it 2-2 before the break.
In Sunday's games, it is: Brest vs. Valenciennes; Toulouse vs. Lille, and Lens vs. Paris Saint-Germain.
