Lennon however was not impressed with a shaky defensive performance from his rearguard.
"They (Loovens and Majstorovic) made a nervy start," said Lennon.
"They let the balls bounce and they weren't getting to the ball first and it's not like them.
"I thought they improved as the game went on but against better teams and better opposition we will get punished so we need to brush up on that.
"[Forster's] decision-making in the first half with the ball at his feet wasn't great but he made a great save second half from [Richie] Foran and that will do him the world of good.
"And I am sure he is pleased with the clean sheet but we all know, particularly those three that we are talking about, that they can play better.
"But today was about getting the result and the performance was secondary and without being over-critical, I am very happy with them.
"It was not by any means a vintage performance from this team but it was solid enough."
Caley boss Terry Butcher was defiant and praised his players.
"We had chances," said the former Rangers and England defender.
"But Celtic scored their first from our throw-in, against the run of play.
"Then from our corner on the right we conceded the second so I was disappointed with that.
"But we kept going and I was really pleased with the way we played.
"We can take a lot of good things into the game against St Mirren next week."