Paris: Lyon snapped Marseille`s eight-game winning streak on Sunday thanks to a second half goal from Yoann Gourcuff which threw the Ligue 1 title race wide open.
The hard-fought 1-0 win at the Stade Gerland was harsh on Marcelo Bielsa`s men, who dominated for large periods of the second half but were caught out by a counter-attack with 25 minutes left.
Marseille saw their lead at the top reduced to four points over defending champions Paris Saint-Germain, who brushed aside Bordeaux 3-0 on Saturday, while Lyon move ahead of Saint-Etienne into third on goal difference with both sides five points adrift.
Nantes are alone in fifth, and six back, after the Canaries won 2-0 at second-from-bottom Evian on Saturday.
The last time Marseille reached eight victories in a row, it was Lyon who broke their streak back in 1998.
Former Ligue 1 player of the year Gourcuff scored the crucial goal on 65 minutes, against the run of the play, when Lyon completely split open the Marseille rearguard.
Alexandre Lacazette picked up the ball on the left flank and found Gourcuff in acres of space just outside the box and the former Bordeaux playmaker was able to tee up his shot before firing past Steve Mandanda into the roof of the goal.
"We started off a bit slowly in the first half but Lyon played well and caused us problems," said Mandanda.
"We got back on top in the second half and were in control but the goal really killed us. We`ve got to shake off this defeat and just keep going, it`s the end of our streak and we`re disappointed to lose but it`s a long season and there`s a lot of good teams out there.
"We have to stay confident and keep going." added the France international.
The defeat was tough on Bielsa`s side who threatened on several occasions to take the lead, notably through top scorer Pierre-Alain Gignac and Andre Ayew who were denied by the excellent Anthony Lopes in the home goal.
Twenty-year-old Benjamin Mendy was also denied by the French-born Portuguese `keeper, who brilliantly blocked with his legs from a first-time shot at the far post, just before Gourcuff struck.
Earlier, Saint-Etienne kept up their bid for a first French title since 1981 with a late 1-0 victory over Metz while Carlos Eduardo scored five goals as Nice dismantled Guingamp 7-2 in Brittany.
Elsewhere, Rennes won for the third time in five home matches and added to Lille`s problems, with a 2-0 victory at their Stade de la route de L`orient.
Ivory Coast winger Max Gradel grabbed Saint-Etienne`s winner when he hit the target with 16 minutes remaining but the star of Sunday`s action was on-loan Brazilian Carlos Eduardo who struck a first-half hat-trick before adding a second-half brace as Nice ran riot at Guingamp.
It was the first time Nice had scored seven goals away from home and equalled their biggest winning margin on the road from 1960 and 1972 when they beat Troyes and Le Mans 5-0 respectively.
Nice`s biggest ever top flight victory was at home in 1949 when they thrashed Rennes 8-0.
The 25-year-old Eduardo, who normally operates as a midfielder, is on loan from Porto and he now has six goals in seven matches.
The three points also takes Nice up to seventh place and eight points behind Marseille.