Liverpool manager Jurgen Klopp insists their squandering of a three-goal lead in the 3-3 draw with Sevilla was a "misjudgement" by his players and he has no concerns about their character.
Two goals from Roberto Firmino either side of a Sadio Mane strike put the Reds on the verge of qualification for the Champions League knockout stage with a game to spare before the first half had even ended.
However, after the break they collapsed, conceding two to Wissam Ben Yedder inside 15 minutes before Guido Pizarro delivered the final blow with a 93rd-minute equaliser.
"Fantastic first half for us, the second half we made a mistake, we didn't carry on playing football," said Klopp.
"We became passive, they scored the first, then it was obvious the atmosphere changed immediately. That gave them a big boost.
"When controlling the game it is not allowed to become passive in a game like this.
"They are human beings. It was misjudgement."
There was an element of history repeating itself as Liverpool led the 2016 Europa League final 1-0 at half-time only to lose 3-1 and six of the players who featured in Basel on that night played some part in Seville.
The character of Klopp's players has been called into question since then but the Reds boss does not believe it is an issue.
"We showed already fantastic mentality against Dortmund (staging a late comeback to win the Europa League quarter-final 4-3), we showed it in a lot of other games.
"Yes it was not perfect tonight but it's not a general problem. It just happened.
"Could we have done better? 100 per cent. Do I think it's a mentality problem? 100 per cent not.
"We opened the door for them, didn't close it, so they could score in the last minute. That's the story of the game."
Sevilla's comeback preserved their year-long unbeaten home record which had looked like crumbling in spectacular circumstances.
Coach Eduardo Berizzo delivered a rousing team-talk at half-time and it had the desired response.
"I told them that you had to play with your soul, that there is no mistake that could not be solved," he said.
"We talked about rectifying, showing the pride we have, and that if we got the goal soon it was possible.
"They had to go out generating a different energy and people would believe. The team came out and infected 50,000 people.
"We took the risk of going for the game, and that speaks of the football bravery of the players."