Nantes recorded an impressive 2-1 victory at Nice to leapfrog the home side into seventh place in the Ligue 1 table.
Michel Der Zakarian's men have now won four of their last five league matches, while Nice - which is the joint top scorer in the top flight along with leader Paris Saint-Germain - has taken just one point from the last nine available.
Nantes took an 11th-minute lead when youngster Alexis Alegue marked his professional debut with a goal by diverting Youssouf Sabaly's cut-back through the legs of Mouez Hassen.
Jules Iloki should have made it two for the visitor, but Hassen made a stunning point-blank save after the home defence's offside trap had completely failed.
That moment proved costly when Nice levelled matters three minutes before half-time. Hatem Ben Arfa's free-kick found its way to the back post where Romain Genevois was on hand to bundle home.
Alexandre Mendy had a goal disallowed for the hosts in the second half, before Kolbeinn Sigthorsson grabbed the winner by converting Yacine Bammou's deflected cross from close range in the 70th minute.