In the delirium of Fleetwood Town’s victory over Premier League champions Arsenal, in perhaps the biggest shock in Carabao Cup history, there were no secrets, no hidden tactics.

Instead, manager Matt Lawlor celebrated the greatest win of his career and the most momentous night in Fleetwood’s history with disarming honesty. “We haven't practised once,” he said, after the League Two side converted five of the coolest penalties you are ever going to see, right up to 19-year-old centre-back Conor Haughey putting their final one top bins. “I'm not going to blag that we had some meticulous penalties [planned], we haven't.”

Lawlor hadn’t been too sure of the rules, either. As Fleetwood were hanging on against Arsenal’s second-half siege and substitute Martin Odegaard threatened to crack the code that was their deep defence with a moment of magic, Lawlor thought his team were clinging on for extra-time until one of his assistants reminded him the English Football League scrapped that years ago. “I thought, ‘Oh my lord, thank God for that’”, he grinned.

But there was commitment, heart and discipline aplenty at (their) Highbury. Fleetwood had lost five of their last seven matches since they knocked out Sheffield United in the third round last month and drew the champions, as if booking the biggest night in the club’s history on the Fylde Coast had distracted them away from an unbeaten start. Lawlor looked at his young squad and accepted they would go through dips of form, but backed them to come good again on the big occasion.

Arsenal had not conceded in the Premier League in three games but they were breached after just 21 minutes to a side that were 18th in League Two and 84 places below them. There was a ruthlessness about the manner the on-loan Fulham forward Aaron Loupalo-Bi targeted the 17-year-old Arsenal centre-back Marli Salmon, one of three teenagers in the visiting line-up, shrugging him aside before finishing past debutant goalkeeper Illan Meslier.

But Fleetwood had to pick at the gaps. Arteta made nine changes from Saturday’s 2-0 win over Everton but still fielded two forwards in Viktor Gyokeres and Kai Havertz who cost a combined £100m. Martin Zubimendi played in the World Cup final three months ago. Arsenal had Odegaard, Eberechi Eze and Bruno Guimaraes in reserve and all three needed to be chucked on. It was only the introduction of Odegaard, though, that created doubt and danger.

And the champions were repelled magnificently. Rhys Bennett, somehow, was in the right place to block a Havertz volley from point-blank after Gyokeres had pulled one back. Jay Lynch, the goalkeeper, lost his voice directing his back-line from side to side. He revealed Fleetwood had taken inspiration from Grimsby, also of League Two, knocking Manchester United of the Carabao Cup last season: if they made it to penalties, then anything could happen.

The clocked ticked down and, suddenly, the finish line was within sight. Then Arsenal were down to 10. Max Dowman had been outstanding in ripping Ipswich, of the Premier League, to pieces in the previous round, scoring twice in a 4-2 win. If there was one player Fleetwood had to be careful of before kick-off it was likely the 16-year-old chosen by Lionel Messi earlier this month to be one of football’s next big things. Harrison Neal’s lunge on him from behind near the touchline was full-blooded. Dowman’s reaction, to kick back at Neal, saw him sent off.

Arsenal, though, were angered, and almost devastating. They had three clear chances to break Fleetwood’s hearts, only for Lynch to save from Ben White and Odegaard and Havertz to head wide. Finally, they could breathe again. Penalties.

And Fleetwood found freedom from reaching the point they had not even prepared to make. The last penalty shoot-out Arsenal were in was the Champions League final, against Paris Saint-Germain, and the quality of Odegaard’s first, ripped into the side-netting, felt unerring. But Fleetwood responded with certainty, each penalty more impressive than the last. Lynch stayed patient as Guimaraes stuttered, and guessed correctly to save and move Fleetwood one away. Haughey did not blink. He took off and did not look back.

With the Sky Sports cameras in his face, live on national TV, his first reaction was to swear, but fair enough. “We've just beaten the Premier League champions,” he said. It sounded implausible. But on Fleetwood’s greatest night, he was right.