Neil Lennon's men, who last month stunned Barcelona 2-1, put in a determined performance on a cold and noisy night at Celtic Park to book their place in the last-16 for the first time since 2007-08 and lift some of the gloom over Scottish football.
An 81st-minute penalty from Kris Commons sealed victory for Celtic after a nervy game where fans and players were only too aware the ticket to the knockout round depended on the other Group G game at the Nou Camp where Barca were hosting Benfica.
Celtic went ahead in the 21st minute with Gary Hooper's low drive after a blunder by Spartak centre back Juan Insaurralde but the Russian side pulled one back six minutes before halftime through Ari's delightful lob.
"I've watched the last couple of penalties and we've missed them so I thought I'd give this one a miss," a jubilant Lennon told Sky Sports.
"Kris showed a lot of character... he deserved the goal. He wrote his name down in the club's folklore."
"It totally justifies beating Barcelona because if we hadn't have qualified then we would have been the team remembered for beating Barcelona but we are more than that now which is fantastic," Lennon said.
Anticipation hung in the air on a tense evening with home fans keeping a close eye on what was happening in the group's other match while their team fought off a spirited showing by Spartak who had already finished bottom of the group.
Celtic nerves were temporarily calmed after they were gifted an opener when Spartak's Argentine defender Insaurralde mis-kicked a long ball from Celtic's Samaras and sent it straight into the path of Hooper who pounced and drilled home.
Samaras and Ambrose went close before Commons' spot-kick sent Celtic through. With confirmation that the final whistle had gone in Barcelona, the stadium erupted and the party got into full swing.
