Brighton came from behind to knock Arsenal out of the Carabao Cup as they won 3-1 in their third-round tie.
Eddie Nketiah put Arsenal ahead at the Emirates Stadium, but the Seagulls hit back through a Danny Welbeck penalty, before second-half goals from Kaoru Mitoma and Tariq Lamptey put the tie beyond doubt.
It was only the second time in 20 seasons that Arsenal had failed to progress past the third round of this competition, while for Brighton it was the first time since 2011 that they had beaten a top-flight side in this competition.
The defeat could in many ways be a blessing in disguise for the Gunners, though, if they are to continue their charge at the top of the Premier League.
Brighton bounce back to reach fourth round
It only took a much-changed Arsenal side 20 minutes to find the breakthrough. Fabio Vieira broke the line with a pass through to Nketiah, who calmly bent the ball past Jason Steele in the Brighton goal.
Seven minutes later the Seagulls were level, however. It was a moment to forget for Karl Hein on his debut, as the 20-year-old slipped when racing out of goal to close down Welbeck, before bringing him down when trying to retrieve the situation. Welbeck then stepped up and sent the goalkeeper the wrong way from 12 yards.
Despite the error that turned the game, Mikel Arteta backed his decision to not play Aaron Ramsdale or his usual No 2 Matt Turner.
“He deserved a chance,” said the Arsenal boss. “He is the first-choice goalkeeper of his national team and that is unusual [for his age]. If I had to pick the team again tomorrow I would play him again, because you need the experience of playing matches. Errors are a part of the game, it’s about how you react to the error.”
Arsenal started the second half stronger and went close though Nketiah is he rattled the inside of the post. But it was Brighton who took the lead on 58 minutes as Jeremy Sarmiento’s run and pass found Mitoma in the box, and he bent his finish past Hein to make it 2-1.
And they had a third on 71 minutes as Lamptey broke into the box down the left channel, showing his trademark burst of pace before sliding a finish under the helpless Hein.
Could a lack of depth cost Arsenal in Premier League push?
It was a chance for some of Arsenal’s second string to test themselves against Premier League opposition, were any called upon by Arteta if needed in the top flight.
But it was a night where few of his supporting cast covered themselves in much glory. The drop-off between the starting XI and what lies beneath will be of concern if they are to last the course and continue their push at the top of the league.
A few recruits in January would not go amiss if they are to continue their current run because a spate of injuries in the wrong places would swiftly derail their progress.
“That’s the squad we have,” admitted Arteta. “We have to try and utilise it as well as possible. But today we came up short. We didn’t do what we needed to do in both boxes to win the match.
“We know where we are and we have injuries in a squad that is already short. We have to manage that in the best possible situation.”
De Zerbi: Brighton can play better
“We can play better,” said Brighton boss Robert De Zerbi. “We made stupid mistakes. But I’m happy for this win because we were a bit lucky in the first part of the second half, as Arsenal could have scored from two or three chances.
“But I’m happy because we have many young players who were playing for me for the first time, and it’s difficult when you’re not playing so much.
“For me it’s very important to have a cup run and for this win against Arsenal. It’s an honour to win in this stadium but we have to think about the next game from tomorrow, and prepare the best we can for the next game. We want to win and to play better.”
Both sides have their final Premier League fixture before the World Cup this weekend. Arsenal head to Wolves on Saturday Night Football, live on Sky Sports Premier League from 7.30pm – with kick-off at 7.45pm.
Brighton host Aston Villa in the first part of Super Sunday, also live on Sky Sports Premier League from 1pm – with kick-off at 2pm.