With two matches to go before the winter break, Bordeaux top the standings on 37 points, Olympique Marseille move to second on 31 thanks to a 2-1 win at Lorient and Montpellier slip to third, one point adrift.
Marseille and Montpellier have a game in hand.
In freezing weather, Bordeaux missed a golden opportunity to unlock a tight game when Gourcuff missed a penalty for handball after a free kick on the half hour.
The champions clinched their fourth league win in a row, the 12th of the season, when Brazilian midfielder Jussie recovered the ball after a bad clearance, sidestepped defender Mapou Yangambiwan and netted a powerful right-footer.
"Montpellier deserved a draw. We won but we played a poor game. Maybe it would have been different if we had converted the penalty," Bordeaux coach Laurent Blanc said. "The good point is that we can win even when we play badly."
Olympique Lyon ended a series of poor results which had pushed them down to ninth place with a hard-fought 2-0 win over second-from-bottom Boulogne, their first victory at home since Sept. 26, and climbed back to fourth on 29 points.
They had to wait until the 72nd minute to open the scoring through Bosnia midfielder Miralem Pjanic. Argentinian striker Cesar Delgado scored their second in added time.
Their supporters however voiced their frustration when they unfolded a banner declaring: "Try harder, respect us" and booed the team to the dressing room.
"The win is a relief for the players. We were a bit shocked at the booing at the end of the game even though we had won," coach Claude Puel said.
Paris St Germain were held to a 1-1 draw at home by Racing Lens despite Claude Makelele's first goal since he joined the club in 2008.
The former Chelsea player scored in the 70th minute but Toifilu Maoulida levelled four minutes later.
Monaco defeated Stade Rennes 1-0, Nancy beat Nice 2-0 and Le Mans moved out of the relegation zone with a 1-0 win over bottom club Grenoble.
