Marseille and Lens both won to top the Ligue 1 standings, beating defending champions Paris St Germain, who will play on Sunday.
An own goal by Nantes defender Nicolas Pallois gave Marseille their second win in three games, while Lens climbed to seven points on Saturday with a full 4-1 away match at Monaco.
Last season runner-up Marseille won 2-1 at home when Pallois deflected a Luis Suarez shot into his own goal.
It took the home side 70 minutes to take the lead with Chancel Mbemba, but teammate Samuel Gigot awarded a penalty six minutes later and was sent off, with Ludovic Blas turning the resulting kick to a draw for Nantes.
But Marseille returned soon after to take all three points.
Previously, Lois Openda and Deiver Machado got Lens two goals behind Monaco before Benoit Badiashile scored one with a header in the 41st minute.
The hosts, however, were completely defeated in the second half, delivering a penalty that Lens captain Seko Fofana converted before Monaco winger Vanderson was sent off for a second yellow card.
Goal substitute Wesley Said added the fourth with a superb right-footed shot at the near post with 12 minutes remaining.
PSG can regain the lead if they win in Lille on Sunday.