Jurgen Klopp admitted Liverpool's 2-1 Premier League home defeat to Crystal Palace "feels so bad" because Sunday's loss was so unnecessary for his side.
Slack Liverpool defending allowed Yannick Bolasie to score with Palace's first shot on target in the 21st minute, and despite Philippe Coutinho's third goal in two games just before the break, Scott Dann exploited more set-piece weakness to grab the Eagles' winner late on.
Alan Pardew's team inflicted Klopp's first Liverpool loss after three wins and three draws, ending the club's longest unbeaten run -- 12 matches -- since September 2013, leaving the former Borussia Dortmund coach frustrated.
"Today is a bad feeling -- it was not necessary to lose this game," he told reporters. "We were better team, but for the first 15 minutes we were not on the pitch. [When] we got the goal, we were awake -- we started creating chances.
"But after the break, we gave them chances to cause us problems. Then we woke up again, but then couldn't make a goal. It feels so bad because it was not necessary. This was not enough for us -- we can do more. We have to learn from this."
The German was also disappointed to see supporters head home after Dann put Palace ahead, and called on his players to make their followers believe they are capable of mounting a fightback and ensure there is no such early exodus in the future.
"After 82 minutes [when they scored] the goal, [there are] 12 minutes to go, but I saw many people leaving the stadium," Klopp said. "I felt pretty alone at this moment. We decide when it is over. Between 82 and 94 [minutes] you can make eight goals, if you like.
"We are responsible that nobody can leave the stadium a minute before [the final whistle] because everything can happen. We have to show [them] and we didn't.
"We decide how strong we are, how good we are, how awake we are, how tired we are: nobody else. We played on Thursday but I decide if I am tired: nobody else."
While Liverpool created a series of chances, Klopp warned them they have to perform for the entire game as he was dissatisfied with parts of their game.
"The problem I have is we play 95 minutes and if you are satisfied with 60, it is sometimes enough, sometimes not," he said.
Defender Mamadou Sakho, who came off with a knee injury and left on crutches, will be assessed this week.
"We have to wait for a scan," Klopp added. "I don't want to speculate now. I would prefer to lose 4-1 and keep him."
ESPN FC correspondent Richard Jolly contributed to this report.