Thomas Tuchel lamented Borussia Dortmund's late loss to Liverpool but was keen to move on, saying "s*** happens".
Jurgen Klopp's side rallied for a remarkable 4-3 win over the German giants, completing a 5-4 aggregate victory in the Europa League quarter-finals.
Dortmund had looked to be cruising at 2-0 up, but Dejan Lovren's stoppage-time header completed Liverpool's stunning comeback on Thursday.
Tuchel felt his side could have put the tie to bed earlier as he rued the late winner at Anfield.
"There was no individual part of the puzzle that did not fit. Actually a lot worked very well today," he said.
"After falling behind early Liverpool had to take a lot of risks. We were on the verge of taking a three-goal lead on several occasions.
"It's the small details that count, the cross-field passes, the passes into the gaps. If we had made it 3-0 then it would have probably been all over, but as it was Liverpool were always in it.
"We were missing the confidence and the presence to calm the game down after they pulled back to 3-2 and to perform against our opponent. At a certain point they were completely driven by emotion.
"Ultimately we were hit by a late sucker punch from the opposition. S*** happens."
Early goals from Henrikh Mkhitaryan and Pierre-Emerick Aubameyang had Dortmund in control at the break.
Divock Origi pulled one back for Liverpool after the interval before Marco Reus restored the visitors' two-goal lead, only for Philippe Coutinho, Mamadou Sakho and Lovren to strike in the final half-hour.
"It feels very sobering. Now we feel very, very empty," Tuchel said.
"We were on the verge of a major aim, a real milestone: overcoming Liverpool at Anfield in a knockout match. We must face the fact that we did not manage it.
"We must be fair and admit that after going 3-1 up we no longer coped with how much risk Liverpool were playing with.
"The trust in our ways of operating was no longer so high, especially under stress and pressure. And thus the worst-case scenario occurred.
"We had a significant cushion but lost the second half 4-1. That is far below the standards that we set ourselves."
