Middlesbrough’s Albert Adomah brought the gripping penalty contest to an end when he fired wide after both teams had kept their nerve in sudden death, shattering the record for the longest shootout in the League Cup.
Liverpool, who have looked a shadow of the team that finished second in the Premier League last season in the new campaign, twice took the lead against their lower league opponents, but defensive errors were once again their undoing.
Elsewhere, Nathaniel Clyne scored with a stunning 30-metre strike as Southampton won 2-1 at Arsenal and Swansea City, who have begun the league season in confident fashion, beat Everton 3-0 with goals from Nathan Dyer, Gylfi Sigurdsson and Marvin Emnes.
In another all Premier League tie, Stoke City came back from a goal down to win 2-1 at Sunderland thanks to a double from Spaniard Marc Muniesa.
Liverpool had gone ahead through debutant Jordan Rossiter after 10 minutes but a familiar failing appeared as Adam Reach was allowed to head home unchallenged midway through the second half.
Spaniard Suso looked like he had given Liverpool victory with a low strike late in extra time, but the hosts imploded with seconds remaining as Kolo Toure conceded a penalty after a terrible backpass from Raheem Sterling. Patrick Bamford slotted home.
Sterling and Bamford were the only players to miss in the shootout, which comfortably surpassed the previous highest score record of 9-8, until Adomah fired off target.
“It was very important to get a result and the players are very happy in the changing room. We’re in the hat and that’s all we want,” said a relieved Liverpool manager Brendan Rodgers.
Middlesbrough’s Spanish coach Aitor Karanka managed to strike an upbeat tone despite coming so close to causing a major upset. “I told the players… I don’t have the words to tell them thank you because they were brilliant.”
Clyne’s wonder goal five minutes before halftime completed a superb comeback for Southampton, who fell behind to an Alexis Sanchez free kick before levelling with a Dusan Tadic penalty.
Southampton, second in the Premier League, have enjoyed a superb start to the campaign after selling several of their most valuable players in the close season and rebuilding under new manager Ronald Koeman.
Elsewhere, third tier MK Dons, who thrashed Manchester United in the last round, won 2-0 at home to Bradford City, fourth tier Shrewsbury Town won 1-0 at home to Norwich City two divisions above them and Fulham beat Doncaster Rovers 2-1.
Second tier Bournemouth won 3-0 at Cardiff City, who were relegated from the Premier League last season, Derby County beat Reading 2-0 and Sheffield United edged past Leyton Orient 1-0. (Reuters)