Rafa Benitez conceded mistakes had cost Newcastle a great opportunity to reach their first league Cup semi-final for 41 years after losing to Hull in a penalty shootout.
The Magpies took the lead in extra-time through Mo Diame, with host side Hull reduced to ten men because of the dismissal of Dieumerci Mbokani, for headbutting Jamaal Lascelles.
However Benitez blamed his players for switching off in the immediate period after the goal and within a minute Matz Sels spilled a shot and Robert Snodgrass swept in an equaliser.
Newcastle, who have won one major sudden death shootout in their history, were woeful from 12 yards once again when the EFL quarter-final went to penalties, with Jonjo Shelvey, Dwight Gayle and finally Yoan Gouffran all missing.
Hull marched through 3-1 winners after Snodgrass, Michael Dawson and Tom Huddlestone keep their cool from the spot and Benitez moaned: “I think it is a missed opportunity.
“I’m very disappointed. You have to be. The way we played we deserved to score goals in the first half and then score goals in extra time. When we scored the goal we did not manage the situation properly. You can get this with experience. Hopefully it will give us this experience and we will do better.
“We can learn for the future. We played really well against a Premier League team away. I was pleased but we still have won nothing. We have to score and win. They had one less player. We had so much control. It was a question of time. We said, now it’s done. We made a mistake and allowed them to score.”
Benitez refused to blame Sels, who was recalled for the tie.
“The team as a whole made mistakes,” he added. “We allowed them to score when we had scored. It is 11 players. We allow them to go to a position we did not want them to. It is a pity when you play so well and go out.”
Hull boss Mike Phelan was delighted with the win but criticised Mbokani for his red card.
“In a moment of madness he reacted,” said Phelan. I spoke with the ref afterwards. I’m disappointed on both parts. I'm disappointed he retaliated which gave the ref no option but to make a decision. I was disappointed because he didn't get much protection the whole game.
“For this football club it’s a tremendous achievement reaching a semi-final. This is the furthest we’ve ever been. That is something for the players, hopefully we can go one step further.”
“Newcastle played decent football. They moved the ball around well but we were good value for money tonight. We’ve got plenty of character. We will need a lot more of it over the next few months.”