Celtic gave themselves a mountain to climb in this play-off round and that only made the view all the sweeter once they had made the summit. Bayern Munich, Real Madrid, Barcelona, Chelsea, Manchester United . . . all of them await in the group stage draw later today. About £16m will pour into Celtic's accounts without a ball being kicked.
Three blows felled Shakhter Karagandy. A goal at the end of the first half from Kris Commons was a release valve for the mounting tension, another from Georgios Samaras levelled the tie and then there was the pandemonium of James Forrest's winner in stoppage time. It could be the most lucrative goal of the wee fella's life. Victory changed Celtic's season and shaped this and maybe the next two or three for the entire SPFL. Celtic's earning power continues to push them further out of sight.
Their pressure and persistence were rewarded. They dominated possession and chances, though not without some hairy moments in defence which encouraged Shakhter to feel an away goal was not beyond them. In truth their superiority was greater than the aggregate margin.
More than 50,000 jittery souls had turned up in the hope that, if their nerves were to be put through the shredder, it would be a price worth paying. It was not a full house but the noise was enough to give Shakhter a shake. Supporters had prayed that this would be a meeting of irresistible force against moveable object, with Celtic's inevitable pressure breaking down modest opponents. The visitors had conceded three goals in their last European away game. Was it really beyond Celtic to do what Skenderbeu, the Albanian champions, managed in the third round?
It was a night for patience, control and discipline. Celtic had to keep probing at the Kazakhs defence and not allow their heads to be clouded by frustration. There was a busy early bombardment which cast goalkeeper Aleksandr Mokin as a major character. He flashed up a hand to push a Mikael Lustig header over, saved a Kris Commons shot, pushed an Anthony Stokes header away at his post and reacted excellently when Commons tried to surprise him with a vicious free-kick. Every save seemed to be showy, as when Stokes tried to beat him again, but Mokin was in the way of everything. Boy, did this character make Parkhead sweat.
The onslaught was never likely to be constant. In the middle of the first half there were 20 minutes when Celtic had plenty of the ball without doing anything with it. Shakhter tightened up and made a better job of getting men behind the ball and creating two walls of orange. They got a foot in to break up a move, they made the necessary tackles, and they were not shy about roughing Celtic up if they could. Andrei Poryvaev required play to be stopped while he was treated, then Gediminas Vicius, their long-throw expert, declared himself a casualty, too. The stands howled at him for timewasting but Vicius protested that he had been the victim of a stamp by Scott Brown.
Shakhter were limited and one-dimensional, but that did not prevent them putting hearts in mouths when they periodically worked their way within sight of Fraser Forster's goal. Too often they flung in crosses and got the first and even second header on them before Celtic were able to shepherd the ball to safety. Lennon had gone with an entirely different central defence than the one which conceded those two soft goals in Astana. Virgil van Dijk was on the bench and Steven Mouyokolo out altogether. Emilio Izaguirre was also among the substitutes. Celtic went for the height of Charlie Mulgrew at left-back and Lustig and Efe Ambrose in the middle. Scott Brown and Joe Ledley held the middle with Forrest right and Commons left. The wide men were fluid, they swapped wings, and they often had Samaras or Anthony Stokes for company on the wings.
Once they had punched themselves out with the early, unrewarded pressure they needed a tin-opener to open the orange defence. Commons was most likely to provide it. He was energetic, bright and hungry, and when he cleverly opened a pocket of space for himself in first half stoppage time the first step was taken towards cutting Shakhter down. He wriggled his way to an opening and struck a terrific shot which at last left Mokin reaching for thin air.
Celtic had a precious goal at a precious time. Then they had another. When Lustig tried a shot at the start of the second half, it fell for Samaras to gracefully sweep the ball inside the goalkeeper's right-hand post. In what felt like the blink of an eye Shakhter's lead had disappeared.
Both teams lived on their nerves. Forrest opened Shakhter up and crossed for Stokes who somehow hit the bar. When Vicius hurled a throw into the penalty area, Celtic's defence switched off and Sergei Khiznichenko was allowed to usher the ball on to the bar. It was the closest Shakhter came to the away goal which turned everything on its head. Celtic would not be denied. It was heading for extra-time until Stokes weaved his way through two defenders and squared for Forrest to thrash home the winner.
The climb was over, and on this summit the only way is up.