Inter Turku came into this tie on a high after beating Istanbul Basaksehir over two legs in the previous round, while Vaduz's 6-0 aggregate win over Atletic Club d'Escaldes proved they were not to be taken lightly.
Yet midway through the first half, Vaduz gave their hosts a helping hand, as Julian Stark turned a Jasse Tuominen corner into his own net to give FC Inter the half-time lead despite the visitors having the majority of the efforts on goal in the first 45 minutes.
However, the Liechtenstein Cup winners pulled level with the first shot on target for either side in the second half, as Dejan Sorgic scored his second UECL goal of the season, hooking in Dominik Schwizer's cross after goalkeeper Eetu Huuhtanen committed himself but didn't claim.
But having finally got the goal they perhaps deserved, Vaduz were behind again just five minutes later, and once again only had themselves to blame.
Sloppy play across the back line allowed Prosper Ahiabu to intercept a pass, ricocheting the ball goalwards. Vaduz goalkeeper Leon Schaffran managed to divert the ball onto the post, but Ahiabu followed up to tap the ball home.
The hosts' Alie Conteh and the away side's Juan Cabrera both had goals disallowed in a frantic few minutes late on, but 2-1 to Inter Turku was how it finished, and they head to Liechtenstein for the second leg on 13th August with the advantage.
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