Madrid top La Liga by a point after five wins out of five since La Liga restarted earlier this month. Real have a game in hand on Barcelona and the tiebreaker edge after the two league meetings.
Even though Real haver a kinder run-in than the Catalans, who drew 2-2 to Atletico Madrid on Tuesday, Zidane warned the trophy could slip from their grasp if they lose momentum.
"It's my job to warn you you've won nothing yet. This is the harsh reality. The truth of the matter," Zidane told a press conference Wednesday.
"There are six games left with 18 points at stake. We are one point ahead, nothing more."
"Being on the right track is one thing, but we will have to repeat this until the end of the season."
Real play Getafe on Thursday in La Liga.
Zidane has a dazzling record with Real Madrid, winning three Champions Leagues n his last spell as manager.
In this season's completion, Real trail Manchester City 2-1 in a last-16 tie that is scheduled to be resolved in England in early August.
"I was a player, I went through this situation, I lived this experience. I know very well what it is, and the players know very well that nothing has been won yet "