Ange Postecoglou rang the bell again. He held his hands to his head in disbelief when decisions went against his team and yellow cards were shown. He fell to his knees in despair when opportunities were missed.
There was also concern about their Uruguayan midfielder Rodrigo Bentancur, withdrawn after appearing unconscious, which was dispelled by a positive update that he was conscious and speaking at half-time.
This time, however, Postecoglou came out smiling. Hitting the air on Lucas Bergvall's first goal for Tottenham gave them a lead to defend as they travel to Merseyside for the second leg of this semi-final in four weeks' time.
Bergvall swept Dominic Solanke's pass into the net in the 86th minute to the fury of the Liverpool bench who were furious for two reasons. They thought the Swedish teenager should have been shown a second yellow card for a mistimed tackle. And two, they were trying to get Kostas Tsimikas back on the field.
Postecoglou didn't care, his emotions were very different from the last time Liverpool fell and crushed his team six times.
More positive, in fact, than in recent weeks, with important late saves from new goalkeeper Antonin Kinsky, one of stunning brilliance to deny Darwin Nunez in stoppage time and a magnificent goal-line clearance from Radu Dragusin.
Lucas Bergvall scored the decisive goal as Tottenham took a 1-0 lead in the first leg of their Carabao Cup semi-final against Liverpool.
Ange Postecoglou smiled after what has been a difficult period for his team.
There was concern about Rodrigo Bentancur, who suffered a serious injury early in the game.
Liverpool achieved a strong finish after sending on Trent Alexander-Arnold, Darwin Núñez and Luis Díaz, but lacked their usual control and fluidity and were beaten for only the second time in 29 games under Arne Slot.
They were sloppy and sloppy by their high standards this season and should have gone behind earlier, when Pedro Porro shot wide of an open goal as Bergvall pushed Alisson into making a mistake with the ball.
Solanke thought he had also broken the deadlock, but VAR ruled out his attempt for offside. Once again, Postecoglou could curse. The first round of the competition when he has been used and intervenes against his team.
When Virgil van Dijk scored to win the Carabao Cup final at Wembley Stadium in February, it was expected to be a goal destined to propel Liverpool forward in their quest for four trophies. In fact, it would be their only trophy of Jurgen Klopp's final season, although it looks like Slot will be the beneficiary of the groundwork put in last year.
Liverpool are high in the Premier League and Champions League and arrived in north London brimming with confidence, just 17 days after beating Spurs six times here in the Premier League.
Spurs, as then, were still exhausted, with 10 missing at the start, although Kinsky, signed from Slavia Prague for £12.5m on Sunday, was included straight into the squad after training just twice with his new team-mates.
The first save of the match was made by Alisson at the other end, a brilliant save, getting down to his right to deny Dragusin a corner, but there was an immediate pause as Bentancur was knocked unconscious as he dived for a header and landed on his face. first on the grass.
There were worrying scenes as teammates and doctors rushed to help. Fortunately, after more than eight minutes of treatment in Liverpool's penalty area, he was conscious when he disappeared down the tunnel on a stretcher.
Tottenham's new goalkeeper Antonin Kinsky made important saves and cut an emotional figure at full time.
Liverpool were left frustrated that Bergvall was still on the field after avoiding a second yellow card moments before his goal.
Trent Alexander-Arnold was knocked out early on, but came on in the second half of the game.
Bentancur gave a thumbs up when Postecoglou came over to check on him, which was a huge relief. At half-time he was talking in the locker room and Spurs sent him from the hospital for further checks.
Fortune seems to be against him. He was withdrawn with a head injury in the opening match of the season at Leicester. And, after serving a seven-match suspension for racially insensitive comments in the media, he returned on Boxing Day only to receive another suspension for five yellow cards three days later. This, his last comeback, lasted less than six minutes.
Postecoglou reorganized and made a tactical adjustment, changing the 4231 shape the Spurs started with toward their more common 433 system. Brennan Johnson came in on the right wing and Dejan Kulusevski moved inside with him and fellow Swede Lucas Bergvall flanking Yves Bissouma in midfield.
Bissouma was booked in the first half, his second yellow card of the competition, but it will not rule him out for the second leg at Anfield because the bookings are annulled in the semi-final.
Liverpool suffered their own injury before half-time, losing Jarrell Quansah. With Joe Gomez out, Wataru Endo was sent in to partner Van Dijk in the heart of the defence. Ibrahima Konate was among the substitutes but only returned from injury on Sunday against Manchester United and Slot was careful.
Kinsky's first real involvement was a couple of panicked moments with the ball at his feet, and his first save came in first-half stoppage time when he stopped Cody Gakpo's long-range effort.
It slipped out of his reach and for a split second looked like it was destined for the net before returning to the young goalkeeper's hands. Kinsky gave a signal to his companions to calm down, as if everything was under control.
Maybe it's an advantage if they've found a lucky goalkeeper.
By then, Dominic Solanke had deflected Heung-min Son's low cross at the near post and Liverpool wasted chances they should have taken better advantage of.
First, Mo Salah shot wide from the edge of the penalty area and then Alexis Mac Allister headed straight at Kinsky when he was unmarked from a free kick.
Liverpool made their changes and the game opened. Porro's miss was followed by Solanke's disallowed goal and Núñez came close more than once at the other end. Perhaps most satisfying for Postecoglou was the way his players defended the clean sheet.
There is work to do if they are to return to Wembley, but this could be the night Tottenham reignite their season.