The former French champions are currently three points behind leaders Paris Saint-Germain following a 3-1 home win against Lorient on Sunday.
"It's a good victory," he told OLTV. "We needed it for our position in the table.
"Our mental strength helped us. I feel good physically, and I'm back playing where I like to. I'm even happier to get a victory.
"I've always said that I'm playing to be champion, all the while knowing PSG were there. As long as we have a chance mathematically, I'll believe."
Lyon last won Ligue 1 in 2008.