A sense of anxiety had to be overcome before Celtic were able to celebrate. Even on a night of great tension, minds wandered from the play here. The home side had to better Benfica's scoreline at the Nou Camp to progress to the knockout stages, but that game finished 0-0 before full-time at Parkhead. Only seconds passed before the referee blew the final whistle, though, confirming Celtic's progress.
Apprehension was evident as Celtic sought the victory. It took until the 82nd minute for the home side to score the decisive goal, by which time doubt had begun to shape their play. A misjudgement came to their aid, since Marek Suchy was rash as he pushed Georgios Samaras over inside the penalty area. The foul was needless, since the Greek striker had his back to goal, but Kris Commons was emphatic in the way he lashed the spot kick high into the net.
Celtic's last Champions League tie in Glasgow was a 2-1 victory over Barcelona and the emotion, the sheer intensity of feeling on that night last month was a backdrop to this game, since Celtic's fate was in their own hands. They only had to better Benfica's result away to Barcelona, and so Celtic Park was filled with that fragile sense of expectation.
The visitors did not need to cope with anxiety, though, and they began the game in a mood of easy accomplishment. There was at least cause for Neil Lennon to be irked, and to rail at his players.
The home side sought to probe at the weak points, and there must have been a sense of familiarity when Juan Insaurralde failed to cut out Samaras's crossfield pass. The defender was sent off in Moscow for a foul on Hooper. On this occasion, his mistake allowed the ball to bounce to Hooper, who lashed it past Sergei Pesyakov from 20 yards out.
But aberrations were possible in both defences and when Efe Ambrose let himself be barged aside by Emmanuel Emenike, the Spartak forward surged upfield before passing to Ari, who chipped a shot over Fraser Forster and into the net.
It only needed moments of ssertiveness in the 82nd minute, though, for Commons to re-establish Celtic's lead. But the game's closing stages became agonising ones for the home side.
However, when Kim Kallstrom was sent off after receiving his second yellow card for a foul on Commons, who was taken off on a stretcher, the result in this game at least was in Celtic's favour.