Zlatan Ibrahimovic's early penalty - the Swede's first PSG goal for almost three months - was ultimately enough to secure three points at Parc des Princes.
Victory helps the champions keep within a point of Ligue 1 leaders Marseille, though Blanc was keen to stress much more is to come from his side, who remain unbeaten this term.
He told Infosport: "Nice played well, we played poorly. Do not look any further than this.
"If you look at the statistics, we did not play so bad.
"It was a good first half but the second was a much more difficult time. Nice played with freedom and could have scored.
"A month ago this would have maybe been 0-0, but if we keep a clean sheet we only need a goal.
"We must learn to be content."
PSG came into the game having overcome Ajax 3-1 in the UEFA Champions League on Tuesday and Blanc conceded the fatigue from their midweek exploits may have been a factor this weekend.
"The physical aspect? It is a parameter, but we cannot hide behind that," he added.
"We won, we took the points, but we did not play well. The truth is there."
