Roux on target as Lille put pressure on PSG
Lille's Nigerian goalkeeper Vincent Enyeama (R) catches the ball during the French L1 football match between Nantes and Lille at the Beaujoire Stadium in Nantes, western France, on October 25, 2013
Lille have 23 points from 11 games, just one point behind leaders Paris Saint Germain who will look to consolidate their advantage at Saint Etienne on Sunday.
Third-placed Monaco, a further point behind Lille, could however reclaim second spot when they host Lyon on Sunday.
"I'm quite satisfied that we're going home with a win and managed to hold this Nantes side who are not easy to manage on their home turf," said Lille coach Rene Girard.
"I was afraid they would snatch victory at the end, but we did the necessary. We have to make the most of this period when we're solid and tough because there could be tougher times coming."
Lille showed their solid defence once again at La Beaujoire stadium with just four goals conceded this season, as Nigerian goalkeeper Vincent Enyeama maintained his record of having not conceded a goal in the last six games.
The only goal of the night came four minutes before the break when Roux found the net despite shades of being offside for his third goal of the season.
Lille resisted a series of attacks from Nantes with an Oswaldo Vizcarrondo header going wide after seven minutes with Vincent Bessat also coming up just short after 27 minutes.
Enyeama did well to hold a Jordan Veretout free kick after 75 minutes and again stood his ground following an effort from Venezuelan striker Fernando Aristeguieta nine minutes from time.
"We lost on a goal that was offside," complained Nantes coach Michel Der Zakarian.
"This is a setback because we lost at home, while we were on a run of four straight wins."
Nantes stay fourth with 19 points from 11 games.
Meanwhile Paris Saint-German coach Laurent Blanc blasted plans by French clubs to strike over the government's 75% supertax, claiming that people "need to see football".
French clubs in the top two divisions voted to strike on the weekend of November 30 in protest at Socialist President Francois Hollande's controversial initiative to tax the super-rich.
It will be the first lockdown in the professional French game since 1972.
"I hope that between now and November 30, which leaves us a little time, a solution will be found," said Blanc, a former French national coach.
"Think about the sport, for the sport, for football, you have to play. People need to see matches."