The Northern Irishman said that Spartak are a good team, but believes that his side were well worth the three points.
"I am probably the proudest man in Europe tonight," Lennon told Sky Sports News. "I cannot speak highly enough of the players, they were magnificent.
"They played magnificent football at a very tough venue against an excellent side. They showed great character and fortitude to come back after going behind just after half-time.
"I thought we thoroughly deserved to win it."
Celtic travel to Barcelona for their next match.