Lyon are two points off the pace in third on goal difference with Girondins Bordeaux having won 3-0 at bottom club Le Havre with goals by Yoann Gourcuff, Souleymane Diawara and Wendel.
Seven times champions Lyon host Sochaux and Paris St Germain, fifth on 52 points, visit Toulouse on Sunday.
"I dare to say I have the title on my mind," Marseille coach Eric Gerets told reporters. "I am delighted to see us at the top but I don't think it will last. I don't think Lyon will lose tomorrow. They will be back at the top of the table tomorrow."
Marseille had to wait until a Renato Civelli header in the 55th minute to break the deadlock after a sluggish first-half. The Argentine defender scored from a free kick by Boudewijn Zenden, who was an inspired halftime substitution.
The Dutchman set up the second goal three minutes later when Brandao capitalised on Zenden's deflected cross to score his first goal at home since joining the Provence side in January.
"We slept during the whole first half but we could have scored some other goals in the second," Gerets said.
LILLE FOURTH
Girondins Bordeaux are second after a 3-0 victory at Le Havre earlier on Saturday, having briefly topped the table.
Gourcuff put Bordeaux ahead when he fired home from close range in the 12th minute after a swift dribble in the box.
Bordeaux failed to create another chance until Senegal defender Diawara headed home a Wendel corner in the 58th.
The Brazilian midfielder made it 3-0 with a trademark free kick in the dying minutes of the game.
Bordeaux had to replace captain and goalkeeper Ulrich Rame and centre back Henrique just before the interval after they were injured running into each other.
"We only aim to be in the top three and there is still a long way to go. Lyon are still a better team than us," Bordeaux defender Diawara told Foot Plus television channel.
Lille showed their title credentials as they moved up to fourth place with a 2-1 home win over Grenoble to stay three points adrift of Marseille.
In-form Brazilian winger Michel Fernandes Bastos put the northern side in front with a penalty in the 11th minute. He then set up Slovak Robert Vittek who tapped the ball into an empty net after a swift counter-attack.
Nice snatched a 2-2 draw at home to second from bottom Caen thanks to a late Olivier Echouafni goal while Monaco earned a 1-0 win at fellow strugglers Nancy through Park Chu-young.
Ireneusz Jelen and Dariusz Dudka gave mid-table Auxerre a 2-0 victory over lowly Le Mans while Stade Rennes and Valenciennes drew 0-0 after both sides were reduced to 10 men.
