After the game, the 43-year-old quipped that his job might not be all that it is cracked up to be.
"I think there was a paradox in the preparation for this game, we were not at all prepared for it," Blanc told BeIn Sport.
"We try to think of every detail and, ironically, this was our best game since the beginning of the season.
"Players returned yesterday at 6.15pm, nothing was prepared and you see the result? The coach is useless!"
The reigning champions are now top of Ligue 1 ahead of tomorrow's round of fixtures.