That was a punch in the testicles for Leicester. After leading at half time and then still holding a share of the points five minutes into injury time, Danny Welbeck came off the bench for his first appearance of the season to head home Mesut Ozil's free kick and cut Leicester City's lead at the top of the table.
There was plenty of controversy in the game, with Jamie Vardy winning a dubious penalty and Danny Simpson getting sent off but the main talking point afterwards was how Welbeck returned to dramatically add another twist to what is already riveting title race.
Louis van Gaal made it very clear early on in his time at Old Trafford that he didn't rate Welbeck as a top striker and allowed him to leave to one of Man United's biggest rivals. The England striker has only scored nine goals in 35 appearances for Arsenal since but his vital header this afternoon probably justifies his transfer fee on its own.
The reaction online was a mix between brilliant memes and shocked reaction - Welbeck hadn't scored a league goal since December 2014.
Danny Welbeck is literally the greatest human being ever to set foot on the earth.
— Tom (@FourFourTom) February 14, 2016
— Des Cahill (@sportsdes) February 14, 2016
Super Danny Welbeck! pic.twitter.com/cIkzwTFD8w
— ArsenalFanTV (@ArsenalFanTV) February 14, 2016
100 - Danny Welbeck's goal was Arsenal's 100th goal scored in 90+ mins of a Premier League game; more than any other side. Drama.
— OptaJoe (@OptaJoe) February 14, 2016
— Arsenal FC (@Arsenal) February 14, 2016
— Mesut Özil (@MesutOzil1088) February 14, 2016
Premier League table:
— Bleacher Report UK (@br_uk) February 14, 2016
With the win, Arsenal have cut Leicester's lead at the top to just two points. However, one positive for Claudio Ranieri's men is that they don't have a to face a team that is currently in the top four for the rest of the season.
They're next four games are against Norwich (H), West Brom (H), Watford (A), Newcastle (H) so the fairytale could still come through yet.