Fleetwood Town teenager Conor Haughey rifled his Carabao Cup penalty into the top left corner to secure a 5-3 shootout win over Arsenal and a quarter-final spot after a 1-1 draw, sparking a pitch invasion at Highbury

Fleetwood penalty hero Conor Haughey has revealed he hadn't even rehearsed spot-kicks before delivering the decisive strike that knocked Arsenal out of the Carabao Cup in what his boss Matt Lawlor called a "mental" upset.

Following Bruno Guimaraes being denied by Jay Lynch, the 19-year-old Haughey hammered his effort into the top left corner, sealing a 5-3 shootout victory after a 1-1 draw and triggering a pitch invasion at Highbury.

Despite his young age, the Northern Ireland Under-21 defender showed no hesitation as he stepped up to take his penalty.

"It's the way I've been brought up," he explained. "Obviously I'm a Belfast boy. Where I grew up, if you're not confident you get eaten up, so you just take it in your stride whatever you do."

His composure was all the more remarkable given he hadn't practised penalties beforehand for a tie in which few would have given Fleetwood any hope – a team sitting 18th in League Two facing the Premier League champions and last season's beaten finalists.

"We all trust in each other's ability, we train with each other every day," Haughey stated. "You already know where you're putting it and just need to be technically good enough to put it where you want to."

Fleetwood stunned the hosts by taking a 21st-minute lead through Fulham loanee Aaron Loupalo-Bi, but Arsenal's introduction of Martin Odegaard at the break altered the momentum and Viktor Gyokeres swiftly equalised as they ramped up the pressure. Fleetwood remained resolute and, following the 85th-minute red card shown to Arsenal youngster Max Dowman for a petulant kick, managed to secure their historic triumph.

Manager Lawlor admitted afterwards: "I'm going to be honest now, I hoped, dreamed and we prepared for a game like that. But if you would have told me that would happen, I wouldn't have probably believed you.

"That we'd be through to the Carabao quarter-final and beating the champions of our country, I think it's mental..

"When it went to penalties, obviously I hoped for a winner. I said to the lads it wouldn't change my thoughts and my feelings on the proudness that I felt in the performance and the way that we dug in and had to dig in.

"Let's have it right, the difference in not just quality, I mean infrastructure, quality, budget. I don't think there's a comparison as to how big of a jump that is, what we've just achieved tonight."

A disappointed Mikel Arteta said: "Congratulations to Fleetwood. I have nothing to fault the players (for) in terms of their attitude, application, the intensity they put in throughout the game.

"But when you are that superior, you give nothing to the opponent apart from the first action that we defended so poorly, and you generate so many situations, actions, volume of shots and chances, you have to score three, four, five, and capitalise on that.

"If you don't there are no margins, that's a reality and then you have to get through the round on penalties. We didn't do that, so the probability is always there."

Arteta revealed he hadn't yet spoken to Dowman about his dismissal, but added: "When we prepared the context of the match, we were very clear on the things to respect, the things that emotionally we have to dominate, it was very clear."