The three goals Arsenal shipped against Manchester United was the first time they conceded three times in a Premier League game since December 2023 against Luton Town.
United sent shockwaves through the division on Sunday, becoming the first team to leave the Emirates victorious this season having won 3-2.
The win was even more impressive considering Arsenal had initially taken the lead, but a first-half strike from Bryan Mbeumo ensured the score was level at the interval.
Patrick Dorgu netted a second for the Red Devils in the second half, but while the Gunners equalised late on, Matheus Cunha scored the winner in the 87th minute.
The last time Arsenal conceded at least three goals in the Premier League was when they beat Luton Town 4-3 in December 2023, and Sunday's match ended a stretch of 83 league matches without doing so.
Premier League title race: Will Arsenal lose out?
The Gunners are still first, but the gap to second-placed Manchester City and third-placed Aston Villa is now four points.
Though that gap is significant after 23 matchweeks, fans will have a nervous eye on their clash against City at the Etihad in April.
Arsenal have been criticised by fans and pundits for their failure to get over the line at key moments, with the team having finished second in each of the last three seasons.
Arteta's side should still be seen as favourites for the title, but his team are now winless in their last three Premier League games, a period that included goalless draws with Nottingham Forest and Liverpool.
If the Londoners finish second yet again, then difficult conversations about the position of the manager may be needed, especially considering he arguably has the best squad in Europe.
Top-four race: Manchester United favourites for Champions League?
United's win left them in fourth place with 38 points, though they are only one point in front of fifth-placed Chelsea and two points in front of sixth-placed Liverpool.
Michael Carrick has overseen victories against Manchester City and Arsenal in his first two games as boss, but his style of play will be tested against teams that defend deep.
The Red Devils will face Chelsea away and Liverpool and home in two of their final six matches of the campaign, but they boast the advantage of having been eliminated from both domestic cup competitions.
Liverpool and Chelsea have to contend with the gruelling demands of Europe, so perhaps United should be seen as favourites to secure a place in the top four due to their lighter schedule.