Rennes went in front thanks to a Cha Du-ri own-goal after half an hour just as Celtic looked to be starting to dominate.
However, Jo Ledley equalised in the 70th minute to hand Celtic a lifeline in Group I.
"It would have been a real shame having played so well to lose a game with the goal we conceded," Lennon told ESPN. "But credit to the players in the second half, we weathered a wee bit of a storm.
"Fraser Forster showed his character, tremendous saves, but we created some good chances and I felt on the balance of play we should have won the game.
"Fraser got himself in no-man's land and you think the curse is going to strike again, but I said to the players 'look, go out there and keep playing, keep committed, keep concentrated' and once we got a good delivery we scored from it which delights me.
"It's a testament to the team after the weekend. They come and show the quality. I'm very very proud of them."
Lennon praised goalscorer Ledley, who played the game out of position at left-back.
"He's a terrific player and no matter where you ask him to play he does a great job for the team," the manager said.
"He's gradually got better and better and he was marvellous against really top class players.
"To get the goal was a bonus but his overall display was fantastic."
Ledley was pleased with his contribution, but praised the team for their fighting spirit after coming back from a goal down to earn a draw.
"I thought I did okay at left-back," he said. "It's not my strongest position but I'm happy to do it for the team and I'm just glad we put in a great team performance.
"We've got some great players here and it was a great performance by the boys."
Celtic striker Anthony Stokes was relieved to secure a point but, like Lennon, was frustrated not to come away with more from the Route de Lorient stadium.
"We knew we couldn't lose this game and it was a massive game for us and we're just glad we got the point at the end but maybe on another day we would have won the game," said Stokes.
"We're happy with the point considering where we were at half-time."