A blistering start against Real Betis had Celtic dreaming of finally ending their pain in Spain at the 20th time of asking. Familiar shortcomings in defence means the wait continues.
Fans' trepidation turned to jubilation as Celtic's patchwork team swept into an early 2-0 lead away to Real Betis, before four goals in 21 minutes provided a stinging reality check.
Manager Ange Postecoglou was "really proud" of his players, despite the 4-3 defeat which means Celtic's record on Spanish soil now stands at 17 losses and three draws across the last 59 years.
In 2003, Celtic scored two in Seville and ended up heartbroken, losing the Uefa Cup final to Porto. This time they netted three in the same city - and still ended up with nothing to show for it.
Postecoglou was keen to focus on the positives, with Celtic displaying the kind of attacking football he aspires to, with Albian Ajeti and Anthony Ralston netting either side of an Josip Juranovic penalty.
In 13 games under the Australian, Celtic have scored three or more on seven occasions. However, on this occasion, they had little to show for it.
"I couldn't ask any more from the players, the football we played was exactly the type of team we want to be," Postecoglou told Celtic TV.
"I don't think there was much between the teams. We probably had an equal amount of chances and they took more than we did.
"Yeah, there are areas we still want to improve, but when you come away from home and score three goals and create many more chances apart from that, I think moving forward there are some good signs here."
Soro struggles as Celtic are overrun
Does Celtic's unwavering attacking ideology come at the expense of any kind of defensive pragmatism?
While they can blow teams away at home, they have proven vulnerable on the road, with five defeats in six since Postecoglou took charge.
Celtic's struggles in keeping Betis at bay weren't confined to their porous defence. Ismaila Soro, filling in for injured captain Callum McGregor, endured a torrid night in the deep midfield role.
The Ivorian was walking a tightrope after being booked just eight minutes in following a couple of fouls on Nabil Fekir. The hosts were screaming for a second yellow after his clumsy lunge later in the half, and Soro was replaced by James McCarthy shortly after Betis went 4-2 up in the second period.
"The biggest miss tonight for Celtic was Callum McGregor," said former Scotland forward James McFadden on Sportsound.
"Soro is nowhere near McGregor's level in terms of intelligence to play the position, quality on the ball, energy, and leadership. It's a huge loss."
Former Celtic goalkeeper Pat Bonner believes Soro wasn't helped by a system that left him isolated, with Celtic now having conceded 10 goals in four European away games this season.
"Playing two holding midfielders away from home in Europe is the way most managers would set up, but Postecoglou won't change," said Bonner.
"Soro needs help in that role from another defensive type midfielder to provide more solidity. Then you might stop losing as many goals, but you may not score as many. It's getting that balance right."
Both pundits agree improvement will come as Celtic's raft of signings at the back acclimatise and form an understanding.
"This is still every days," Bonner said. "Cameron Carter-Vickers and Josip Juranovic have just come into the team, Carl Starfelt has only played a few games."
McFadden added: "The difficulty for Celtic this season is they have had so many defensive partnerships and you need to allow a pairing to grow."