Underestimate Bodo/Glimt at your peril, Tottenham.
Just ask Porto, Besiktas, Olympiakos and Lazio this season. Roma and Celtic, who were managed then by Spurs boss Ange Postecoglou, were also victims four years ago.
The most recent giant-killing of Lazio, though, was particularly historic as Bodo/Glimt became the first Norwegian side to reach a European semi-final.
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Now the Eliteserien champions, located above the Arctic Circle, are aiming to freeze out Spurs, whose stadium is astonishingly bigger than Bodo's population of 55,000.
"We walk into this game with confidence that whoever we meet, we believe we're able to compete," says Bodo/Glimt's sporting director Havard Sakariassen.
"I hope that we don't focus on the occasion and that we play the game and dare to be ourselves.
"I truly strongly believe we have all the tools to be brave enough to go out in London and just be Bodo/Glimt. Just play the game, and then we will see.
"Of course, the experience that we have gained over the last years makes us more confident in situations like this."
'We have cracked the European code'
One of those pivotal experiences came in north London in October 2022, as Bodo/Glimt suffered a 3-0 Europa League group-stage defeat at Tottenham's rivals Arsenal.
But the loss at the Emirates Stadium proved key in solving the European puzzle.
"I think we have cracked some codes regarding performance, especially away," Sakariassen says.
"To be more cynical, not to be naive playing away against good teams in Europe.
"At home, we want to go out, dominate teams and have possession. Away in Europe we try to do that, but of course sometimes you meet teams that are truly, truly good.
"It's hard to find the weakness in the team, and you can't be naive playing against these teams. You may have to adjust the mindset. It's hard.
"When we went to Arsenal, they were leading, it was hard to go and dominate. You have to attack it in a different way and try to be smarter. It's something that comes with experience.
"We've learnt a lot because we've played decent away games this year in pressured situations. It's smartness in the play and to reckon sometimes a good performance is to be truly good in your defence."
Spurs will have their own conundrum to figure out - Bodo/Glimt's 8,270-seater Aspymyra Stadion. An artificial pitch and freezing temperatures have made it an icy enigma for visiting sides.
Postecoglou's team will need togetherness and teamwork to pass the test, something their opponents have in abundance, with the majority of the squad from Norway.
"I think it has a value in itself, in your life, to be able to play at this level in your hometown, also with your friends," Sakariassen says.
"So I think the culture in the club here is something they really enjoy...but I think it has to be rare to be able to play football with your mates at this level anywhere in Europe, and that has a value."
But Bodo/Glimt's band of brothers go to the Tottenham Hotspur Stadium for the first leg facing an absentee crisis.
Influential captain Patrick Berg, his midfield partner Hakon Evjen and striker Andreas Helmersen are all suspended, while key centre-back Odin Bjortuft is an injury doubt.
All four were part of the starting XI as Bodo/Glimt lost 3-2 at Manchester United in November despite going 2-1 up. Sakariassen wants another go at Ruben Amorim's side in Bilbao on May 21.
"I'm actually a (Manchester) United supporter from back in the day, so Bodo vs United sounds great for me," he jokes.
From brink of bankruptcy to potential Europa League final
Talk of Bodo/Glimt being in a Europa League final would have been unthinkable a decade ago.
He reveals that during his playing days for the club they were "nearly bankrupt", and he has previously spoken of a time when the squad had to wash their own kit.
Their budget in 2017 was a paltry £3.6m (€4.2m). Seven years on, their revenue was £51m (€60m). The fairytale is even more magical considering it was financially organic.
"Nobody has given us money outside the prize money in these 10 years," Sakariassen says. "It shows that you can achieve stuff if you work well over time, and that is the main part of it, but it's much easier if you have money.
"I know that people have said to me that we are an inspiration that you can achieve with a small club.
"I would find inspiration in a story like this if you go back 10 years ago. Smaller clubs can get inspired, and it takes a whole lot of hard work and a lot of luck throughout the way to actually make it happen."
Sakariassen also believes patience has been vital in their meteoric rise, which has seen them win four of the last five Norwegian top-flight titles, with their first Eliteserien coming in 2020.
'I'm not afraid of interest in boss Knutsen'
The frontman for their success is manager Kjetil Knutsen, whose brand of football has been described as "kamikaze" by midfielder Ulrik Saltnes.
Asked by Sky Sports about the Norwegian tactician, Sakariassen replies: "It's his eighth year here, so we have been on a long journey together trying to build Bodo/Glimt to what it is today.
"He's a man of true passion about football and about this project. It's impressive for him, but also for many people who have worked over the last eight years with the kind of success that we have achieved.
"We come in every day with him as a leader to seek improvement every day, even after winning a trophy or achieving something.
"So number one, he's famed for the project, to actually live it through and through.
"Also, his loyalty to the club, the fans, the city and the loyalty that we have for each other is quite unique in professional football anywhere.
"With the kind of success Bodo/Glimt has had in the last years, it's quite unique and says a lot about him that he's still here."
But that loyalty could be tested seriously soon with the 56-year-old linked with Rangers and Leeds.
Asked by Sky Sports whether he was worried about interest in Knutsen, Sakariassen responds: "No, I'm not afraid of anything.
"Of course, Kjetil is an attractive manager, that's just the nature of what we do.
"Whatever happens, happens. He's been here for eight years and has probably had some really good offers along the way.
"I know that he enjoys being in Bodo, enjoys working at this club. Should he, for some reason, decide to do something else I think we should applaud him to the airport and say thank you.
"But I'm not afraid of that at all, and I think that we will work here for more years to come - but who knows?"
What is for certain is that Knutsen and his players are ready to crack another code on Thursday.