Blanc's men were made to work hard to take the three points at the Stade du Hainaut on Wednesday, Edinson Cavani's third goal for the club enough to secure victory.
It was a far from stellar performance from PSG, who were without captain and influential defender Thiago Silva due to a hamstring injury picked up in the draw with Monaco at the Parc des Princes on Sunday.
Former France manager Blanc accepted that his side been nowhere near their best, and felt that the Brazil international's absence had a big impact on thier performance.
"(PSG were) in pain on the pitch, but also off the pitch because there are some injury problems," Blanc said.
"This was a difficult match in every sense of the word, but the main thing is to have taken the three points because there will be many matches like that this season.
"In the Monaco match we burned a lot of energy, we only had three days to recover and we lost Thiago (Silva)."
PSG had been boosted by the news that striker Zlatan Ibrahimovic - who set up Cavani's winner - has agreed to extend his contract with the club, keeping him in the French capital until 2016.
Blanc is understandably happy to have kept the Swede at the club, praising the PSG hierarchy for their ambition.
"Great players staying with Paris gives me pleasure," he added.
"It shows the ambition of the club to do great things and that Ibra wanted to continue in the project of the club.
"It is good for me and the club because it is nice to see a player like this.
"Tonight he showed his class and that makes all the difference."
