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.
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 Mikel 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.
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.