The roar of relief was everything. Tottenham could not afford to mess up this opportunity but Ange Postecoglou’s side held firm, knocking Manchester City out of the Carabao Cup to hand Pep Guardiola’s team their first defeat of the season. Tottenham’s ability to self-destruct ensured this was still a gripping cup tie, even as City chased the game in second gear. It was almost enough and although Bernardo Silva’s protests at full-time suggested City wanted to win this just as much as Spurs, the sight of Erling Haaland grinning on the bench, an unused substitute even as City trailed for over 90 minutes, told a different story.

There is no question how much this meant for Spurs. Postecoglou has talked up his tendency to win trophies in his second season and, although he is still unable to conjure consistency from his side, Spurs held on to win their biggest game of the season so far when the pressure was on. That the Premier League champions were far below their best and finished with four teenagers on the pitch, plus another academy graduate in the 22-year-old James McAtee, makes little difference to Spurs in the grand scheme of taking a step closer to ending their 16-year trophy drought.

With City out, Postecoglou laughed at the suggestion that the Carabao Cup was opening up in Tottenham’s favour. Moments later, Spurs drew Manchester United at home in the quarter-finals. “There’s always an opportunity if you keep winning,” Postecoglou had said. “The most important thing is we’re still in it.” The Australian also praised Tottenham’s resilience and, although City were understrength, they answered a big series of questions here. “I’m not going to go for ‘big steps forward’ or ‘big steps back’,” Postecoglou added. “I continue to see growth in this group and this team.”

Guardiola had promised not to waste any energy on the Carabao Cup. Still, the injuries piled up. Guardiola lost Manuel Akanji in the warm-up and the impressive Savinho was stretchered off in the second half. The least important of the four cup competitions City are involved in this season has still paid a price. Guardiola did not quite field the weakened side Tottenham had hoped for, but his team were largely unrecognisable and often lacklustre in possession in the first half. The manager grew increasingly exasperated at the misplaced passes in midfield and the basic errors his players were making.

Tottenham were clinical when it counted. Dejan Kulusevski, who has a fine record against Guardiola’s team, had the running of midfield, driving through the space that opened up as a result of City’s sloppiness. He set up both goals. The opener was an excellent, back-to-front counter attack, finished first time by Timo Werner for his first of the season. Then Spurs caught City cold from a fine corner routine. Kulusevski picked out Pape Matar Sarr, who curled a sublime finish past Stefan Orteta from 25 yards. “Both goals were outstanding from us,” Postecoglou agreed.

Still bruised by Sunday’s 1-0 defeat at Crystal Palace, Postecoglou’s side had at least showed up. The question became how they would respond to adversity. Spurs suffered the blow of Micky van de Ven limping off with a hamstring injury, feeling the back of his leg immediately after chasing back to tackle Savinho, a moment where the atmosphere started to shift. Van de Ven was replaced by Destiny Udogie but the left back’s defensive weaknesses were soon evident: Savinho skipped past him to set up Mattheus Nunes as City pulled one back on the stroke of half time.

The goal had been coming; to Postecoglou’s clear frustration his side could not make it through the four minutes of added time to regroup at the break. City were far sharper after falling two goals down and Phil Foden, deployed at No 9 in place of Haaland, had spurned two presentable opportunities before an unmarked Nunes fired in at the back post. Tottenham had retreated and the home fans were on edge as they invited further pressure. Cristian Romero was also forced off, as Tottenham lost their first-choice centre-back pair.

Perhaps there was further reason for Tottenham to sit in. Postecoglou’s counter-attacking approach clearly suited Spurs and the hosts had the chances to be out of sight after half time. Werner, unable to build on his early show of ruthlessness, fired wide when sent clean through. Stefan Ortega made two wonderful saves, to deny Brennan Johnson’s deflected shot and Kulusevski’s low finish on the break. Richarlison spurned the best opportunity of all late on when Josko Gvardiol’s errant throw-in put the Brazilian through, only to shoot straight at Ortega.

It would have been typical Spurs had City nicked an equaliser and the final 15 minutes brought relentless pressure, even as Haaland remained wrapped up warm on the bench, watching as Jacob Wright and Jahmai Simpson-Pusey were called into action ahead of him. Wright curled just wide before Yves Bissouma made an extraordinary clearance on the line to poke Nico O’Reilly’s downward volley wide. The midfielder was mobbed by his team-mates before Spurs could properly celebrate at full time.

Postecoglou may disagree that victory over City was an important step forward, but December’s quarter-final against United may feel like his biggest game in charge when it comes around.