Lennon, as promised, made nine changes with this week's first leg of their Champion League last-16 tie against Juventus in mind and was rewarded with a convincing display.
Debutants Tom Rogic and Rami Gershon especially caught the eye, with the 20-year-old Australia international, signed from Central Coast Mariners in January, claiming the man of the match award.
Israel defender Gershon also grabbed his first Celtic goal to send the visitors ahead after they fell behind to Nick Ross' early opener which had been cancelled out by Kris Commons.
Defender Marcus Fraser started in the SPL for the first time while there were rare starts for Paddy McCourt, Dylan McGeouch and Venezuelan striker Miku, who grabbed the third with eight minutes remaining.
Lennon said: "I am delighted and I think you saw a wee glimpse of what is coming through. Marcus Fraser, Dylan McGeouch, Rogic - young players who I thought were fantastic.
"Tom has settled in very quickly. You feel sometimes that there will be a wee readjustment period but he has settled in very quickly.
"We know Rami is powerful in the air and he scored a great goal. He had a great debut.
"The players on the cusp of the first-team squad like Thomas Rogne and Miku came in and did well.
"So all in all, to come here to a side in second place who were playing their first team, and to win with that team we had, speaks volumes for the performance of the players."