Goals from Clement Chantome, Zlatan Ibrahimovic and Lucas Moura at Altrad Stadium were enough to secure the capital club's place in the round of 32 on Monday.
The pitch at the Altrad Stadium in Montpellier - the local rugby venue - was less than ideal but Blanc was delighted it didn't stop his player's getting the job done.
Montpellier's regular home ground - the Stade de la Mosson - was unavailable due to flood damage.
"I am satisfied with everything, especially the game put on by both teams, because on a pitch like that, it is hardly possible to offer a good game," Blanc told Eurosport.
"There was commitment and opportunities. For that alone, the game was interesting. It was important for us to start on a positive note and we did that."
It has been a tumultuous week for the Parisian side after South American duo Edinson Cavani and Ezequiel Lavezzi were both fined and banned for two matches after returning late from the Christmas break.
However, Blanc is confident the victory over Montpellier will galvanise his side as they turn their attention to a Ligue 1 clash with struggling Bastia on Saturday.
"I really hope that despite our small problems right now, this victory will help to strengthen the group," Blanc said.
"Now we have to do it again on Saturday against Bastia. The best answer is to be good on the ground."
Goalscorer Lucas Moura echoed his coach's sentiments, insisting the win can act as a catalyst for a strong run of form for the reigning Ligue 1 champions, who currently sit third on the table.
"I think we had a good game, because it is always very difficult to play against Montpellier, a team that defends well," the Brazilian said.
"We must play like this more often and give everything together. If we continue to play like that, we can go very far."
