Liverpool put on the spot again by their leaky defence
It was a night to remember, the longest penalty shoot-out involving any top-flight English club. However, although his side won it, Brendan Rodgers cannot afford many more triumphs like this.
When all the high emotion of winning 14-13 on penalties had faded into the Anfield night, the Liverpool manager would have asked himself how, even facing an exceptional Middlesbrough side, he came to be dragged into a shoot-out at all.
He would have known the answer. Liverpool's defence, without Glen Johnson and Martin Skrtel, is not good enough.
After the match, he remarked that both Boro's goals - a set-piece that saw Adam Reach slip away from Jose Enrique and a penalty ridiculously conceded by Kolo Touré in the last seconds of extra-time - were entirely avoidable. The 2-2 draw meant Liverpool have kept a single clean sheet this season.
"We are making far too many mistakes," said Rodgers. "I was disappointed with both their goals, especially the second because by then Middlesbrough were tired and their legs had gone."
You wondered how heavy Raheem Sterling's legs were feeling the morning after. Given that Rodgers had emphasised how important it is to rest Sterling lest he suffer the kind of burnout that afflicted Michael Owen and Robbie Fowler in their 20s, it was a surprise that he started, let alone played every minute of a tie that finished at 10.42pm.
Rodgers argued that last season they had been forced into a rather shorter penalty shoot-out with Notts County and then beaten Manchester United in their next game. Everton, who Liverpool face in Saturday's Merseyside derby, had an equally wearying journey back from south Wales, and they had lost.
Sterling was the only one of Liverpool's players to miss from the spot on Tuesday night, which should have led to some familiar comments about England internationals and their failings from 12 yards had Adam Lallana not put away both of his penalties emphatically.
The standard of penalty taking was so extraordinarily high that it could almost have been played out in front of Dortmund's Yellow Wall rather than the Kop.
There is little point arguing that because it was 'only' the League Cup the takers were more relaxed than they might otherwise have been. Every step the Boro players took towards the spot was greeted with a howl of derision.
Failure in a shoot-out in a League Cup tie against Northampton was the first real indication that Roy Hodgson's regime at Anfield was doomed.
Rodgers had put out a very strong side. He may have transformed Liverpool's play but he has yet to win silverware, and no cup can be ignored.
Although Rickie Lambert's first start in a Liverpool shirt was overshadowed by that of Jordan Rossiter who, 15 years younger, scored the opening goal with his first shot, the England striker would not have taken the night lightly, not least because he captained the side.
Born in Kirkby, not far from the Liverpool academy where Rossiter receives his football education, Lambert did not have to be persuaded to return to Merseyside. It was a bold move by Rodgers since a big, classic English centre-forward is not the type of player associated with his favoured style of play. Lambert gives Liverpool a Plan B, though he went home dissatisfied with his evening.
"I wasn't happy with my performance so that overshadowed the honour of being captain a little bit," he said. "It was just things, touches. I didn't feel as sharp as I want to feel. I want to get my match fitness up because everyone knows I am not going to play every game and I have to adapt myself now."
Given that Lambert had missed a penalty in a shoot-out between Macclesfield and Forest Green that finished 11-10, it was perhaps a mercy he watched it from the bench. (© Independent News Service)