Reiss Nelson scored a stunning 97th-minute winner as Premier League leaders Arsenal came from two goals down to beat Bournemouth.
Bournemouth had taken the lead after just 9.11 seconds through Philip Billing, and went 2-0 up via a Marco Senesi header.
However Arsenal pulled level with goals by Thomas Partey and Ben White, before Nelson struck.
The winger, making his first appearance since 12 November, slammed in from 25 yards in the seventh minute of stoppage time.
Arsenal’s Premier League lead is restored to five points, after they had seemed certain to cede ground to Manchester City, winners over Newcastle in the early kick-off.
Bournemouth, meanwhile, remain in the relegation zone after threatening a major upset – and beginning at top speed.
Billing’s goal was the second-quickest in Premier League history – only Shane Long, who scored for Southampton after 7.69 seconds at Watford in April 2019, has netted faster.
Nelson colossal as Arsenal snatch victory
Nelson had played just 64 minutes of Premier League football this season – having struggled with thigh problems – before being thrown on as a second-half substitute by Mikel Arteta here.
Yet the homegrown talent was the unexpected hero, collecting a half-cleared corner outside the area and bending a superb strike beyond Bournemouth keeper Neto.
The outpouring of emotion that followed was immense; the Arsenal bench cleared as virtually every player and member of staff rushed to celebrate with the match-winner.
Nelson had earlier, with practically his first Premier League touch of 2023, provided the assist for White to equalise with his first Arsenal goal.
White, brought on as a half-time substitute after Takehiro Tomiyasu endured a torrid 45 minutes, struck Nelson’s deep cross first time and his shot was palmed away from behind the line by Neto, with referee Christopher Kavanagh giving it via goalline technology.
What is remarkable is that Nelson, had everything gone to plan for Arsenal, would have been very unlikely to reach the pitch. He replaced Emile Smith Rowe, himself a sub for Leandro Trossard, who suffered a first half injury.
However it is with unexpected twists, remarkable moments and incredible goals that titles are often won.