Lazio midfielder Senad Lulic admitted his side got everything wrong in the second half against Red Bull Salzburg and "crumbled" in their disastrous elimination from the Europa League.
Ciro Immobile had looked to have booked the Italians' last-four berth with a fine finish 10 minutes into the second half, putting them 5-2 ahead on aggregate.
However, Munas Dabbur set up a stirring comeback by cancelling out that strike just two minutes later before Amadou Haidara, Hwang Hee-chan and Stefan Lainer all scored in the space of four minutes to complete a remarkable turnaround.
And Lulic had no excuses in his post-match interview, declaring his side's "inexplicable" inability to do anything right during that stretch of play.
"Everything we were meant to not do, we ended up doing," he said. "It was such a good start, but we crumbled and it's just inexplicable.
"All you need at this level is to lose concentration for 10-15 minutes to concede four goals. You pay for that.
"I don't think it was a physical issue, but a psychological one. We had a total black-out and everything went wrong. We should've controlled the result better."
Lazio head coach Simone Inzaghi took a far more diplomatic approach, refusing to criticise his players and adding he believes it will be a valuable experience for them.
He told Sky Sport Italia: "The difference is that we had the same number of shots on goal today, they scored four and we got one. We'll learn from this and it'll help us to grow.
"It was an emotional journey. It's a shame we couldn't give them this semi-final, which was right there in front of us.
"I don't think we were defensive this evening at all. We had the scoring opportunities and simply didn't take enough of them. The two goals they scored in Rome were also somewhat fortuitous, but we move on.
"I am sure it'll be another step in the growth experience, as let's not forget we have many young players in their first European campaigns."
The capital club must now turn their focus back to Serie A, where they remain in a heated battle for the top four. Lazio sit in third on 60 points, ahead of city rival and Champions League semi-finalist Roma on goal difference. Meanwhile, Inter Milan sit just a point back of the two capital clubs in fifth, while AC Milan hang eight points back in sixth.