St Johnstone boss Callum Davidson revealed his players came away disappointed after a 1-1 draw against LASK despite setting up an "enormous" second leg in Perth.
Scotland's double cup winners more than held their own against the Austrians with a place in the Europa Conference League group stage at stake.
Saints led through Chris Kane's close-range strike and created a string of chances early in the second period, with Glenn Middleton taking a heavy touch when he looked odds on to convert after Michael O'Halloran's break.
Moments later Jamie McCart conceded a penalty with a needless challenge which allowed Mamoudou Karamoko to level on the hour mark, but Saints were again mostly comfortable until surviving some late scares.
The result mirrored St Johnstone's 1-1 draw at Galatasaray in the Europa League, but Davidson's side performed even better in Austria than they did in Istanbul.
Davidson said: "We will have a great atmosphere again at McDiarmid, we got a full house last time.
"To qualify for this league is probably as big a game as St Johnstone have had in their history, so it's an enormous game.
"The people of Perth, they missed out on two cup finals last season, and to be fair this is a cup final for us on Thursday."
LASK reached the last 16 of the Europa League in 2019 but the Saints players were far from overawed.
"They believe in themselves," Davidson said. "They are all disappointed in the dressing toom with conceding the penalty, and probably the last five minutes. But that sums them up, where their mindset is just now.
"For St Johnstone to come away probably slightly disappointed with a draw, it shows the expectations and how we performed.
"I was absolutely delighted. If you asked me to go and play LASK with their European pedigree and come away with a draw and give ourselves a chance to qualify for the league, then I would have taken it.
"They followed the game plan, they were brilliant, tried to play the right away. Probably being critical, we could have transitioned the ball a bit better, but that's me being critical.
"Disappointed when Michael had a great run and slipped the ball into Glenn and he is probably the person on the pitch I expect to score, then two minutes later we concede a penalty.
"But that's football. A bit disappointed with that but we hung in and battled, had another chance."