Moments to delight Ange Postecoglou - a goal on his debut for Kyogo Furuhashi, another strike from Liel Abada - were interspersed with others at the back to have him watching through the cracks of his fingers.
That was the case with the two goals conceded; strikes that caused Celtic to be pegged back to 2-1 just after they had doubled their advantage a quarter of an hour in, and 3-2 in the closing minutes - only for Ryan Christie to restore a two-goal cushion in the final seconds of normal time.
Chances aplenty were missed and, on his first outing, keeper Joe Hart wasn’t able to bring command to a backline that seems shaky not just for the personnel deployed there, but for the focus on forward movement demanded by the Celtic manager.
Yet, ultimately, the first win for Postecoglou in his fourth competitive match will bring palpable relief...even if that comes with genuine concerns. And, it should be noted that the result, which should set up his team to progress in the home return leg next week, was the first Celtic have registered in nine games on the road.
As Postecoglou brings ever-more new faces on board, the club’s support treat the arrival of a Celtic team sheet like a Marvel Extended Universe reveal. Lauded by some, lashed by others, and picked apart for the unexpected and the all-too-familiar. And on the night, the craving for would-be super heroes to emerge from the faithful would have been assuaged by the inclusion of Hart and Furuhashi. The selection of the former England goalkeeper was a given, but the Australian’s decision to hand Furuhashi his first start as a central striker and at the expense of the, considered to be, attitudinally-challenged Odsonne Edouard proved a twist that was celebrated.
The bold move suggested that Postecoglou isn’t going to be afraid to make big calls. The fact he has moved as rapidly as humanly possible to integrate as many of his signings, four in his latest line-up wth Abada and Carl Starfelt also in the ranks, told of his lack of faith in what he has inherited.
It seemed risky to essentially fill all areas of the team with players hardly yet on nodding terms with each other. Perhaps, though, that in part reflected what he deduced about the sttength of his Czech hosts. In truth, Jablonec were a team striving to be of the modest variety, irrespective of their third place finish in a decent domestic set-up.
Celtic’s sharpness and dominance of possession early on gave the impression that Postecoglou’s men would really put their opponents to the sword. There is an openness about them, though, and a wastefulness in front of goal that doesn’t appear to make anything straightforward for them. Those issues accounted for the fact they hadn’t won across the two ties of their Champions League vanquishing by Midtjylland, before contriving a defeat in their cinch Premiership opener to Hearts last Saturday.
Ultimately, though, they achieved a perfectly acceptable outcome and did so with Postecoglou’s signings making positive impressions. Abada patently has goals in him, and might have put himself on the scoresheet even before he opened the scoring in the 12th minute. The winger did so then, following good combination play down the left by James Forrest and Greg Taylor. It produced a cut-back from the left back that Abada buried after his initial attempt was blocked.
And when Celtic’s advantage was doubled three minutes later, it was all about the exquisite endowments of Furuhashi that Postecoglou is pinning great hopes on. As well, it must be said, of Nir Bitton’s talents, the much maligned Israeli gliding forward into the final third before delivering a perfect ball for his new team-mate to run through on. A sublime touch to flick it forward was followed by another to scoop the ball over advancing keeper Jan Hanus.
That should have opened the floodgates. Instead, it was Celtic’s defensive leakiness that reared up only a matter of seconds later. With alarming ease, Vaclav Pilar was able to run on to a simple ball over-the-top and give the stranded Hart no chance from a tucked-away finish.
With Furuhashi’s movement good, and Abada having further openings that went abegging, Celtic were denied comfort. It seemed to have been earned when James Forrest claimed his 13th European goal - only six players have now scored more for the club - when he clipped in the rebound after Abada had yet one more effort saved.
Yet, their flawed defensive make-up betrayed itself six minutes from time when Tomas Malinsky sold Starfelt before lobbing Hart with the keeper way out of his goal, the ball rattling the post before Bitton helped it in when attempting to knock it away.
Yet, the tie had won more swing, substitute Christie producing a stunning header in flying through the air to bullet in a hooked-over cross from the right from Forrest. On an evening when Celtic showed their split personality, their better face just about won through.
FK Jablonec: Hanus; Surzyn, Martinec, Zeleny, Krob; Plestil (Malinky 63), Kubista (Kubista 85), Povazanec (Hubschman 86), Kratochvil (Houska 74), Pilar (Holik 78); Dolezal. Subs: Vanicek, Stepanek, Vajner, Smejkal, Haiti, Hruby.
Celtic: Hart; Ralston, Bitton, Welsh, Taylor; Soro, McGregor; Abada (Christie 64), Turnbull (Rogic 64), Forrest; Furuhashi (Edouard 64). Subs: Barkas, Ajeti, Urhoghide, Bain, Robertson, Murray, Montgomery, Welsh.