The Stade de Gerland outfit scored three times in the final nine minutes to blow out the scoreline at Bordeaux, and Fournier admitted their opponents were curbed by the loss of Nicolas Pallois to a 65th-minute dismissal.
Lyon go into the mid-season break in second spot, behind Marseille by two points.
"It is a beautiful night, and a nice conclusion to the first half of the season, and it will give us some motivation for the second half," Fournier said.
"We played a solid first half, we forced Bordeaux to run a lot and then during the second half - maybe because of all the games played before, every three days - we felt like we had more gas.
"They gave us a lot of space, which was useful because of our quality players.
"I have to say that the red card given to Pallois made it very difficult for Bordeaux."
Fournier's men are also one point clear of Paris Saint-Germain - having won two more matches than the champions - but the 47-year-old coach pleaded for his side to keep their form in perspective.
Lyon won just three of their first eight outings this term, but have claimed all three points in all but two of their 11 fixtures since.
"This generation of players is improving, they are getting confident," the former Reims boss said.
"But I have to calm everybody down, we can't forget that it goes really fast each way.
"Let's not forget that after the fourth game, we were trailing Bordeaux by seven points and we were 17th in the league.
"Fifteen games later, we turned it around, so it can go really fast."