Thiago Motta's goal towards the end of the first half was enough to seal a 1-0 victory for the Ligue 1 leaders and move them 11 points clear of Monaco, who play Lille on Sunday.
Lorient caused PSG plenty of problems on Friday evening, yet a lack of quality from strikers Jeremie Aliadiere and Vincent Aboubakar let the visitors off the hook on a number of occasions.
Blanc admitted his night could have been a lot easier had PSG netted a second goal, but remained satisfied with a sixth straight league win.
"We had a tough game, especially in the first half because we had to adapt to the synthetic pitch," he told beIN Sports. "And then there is the quality of Lorient, who are a team that likes to play passing football and play fast.
"We missed the opportunity to put a second goal that would have allowed us to be more serene.
"This is a good win, because it is always difficult here, especially against a team in form and motivated to fight.
"We were not great but we did what was necessary to win a hard-fought victory."
There were concerns during the first half when PSG captain Thiago Silva left the field due to a head injury.
Blanc remains hopeful there will be no lasting damage, but suggested the Brazilian had been caught by a wayward elbow.
"He (Thiago Silva) has a big bump (on his head). He was put on ice," the coach added. "He received a nasty blow.
"When you jump like that, with the elbow, that hurts.
"But it is nothing serious - I hope anyway."
