With referee Chris Kavanagh poised to blow the final whistle in the seventh minute of stoppage time a corner was cleared out to Nelson who took a touch before smashing home a left-footed shot to spark bedlam inside the Emirates Stadium.

"It was madness from the first second. We kept trying and dominating the game. We had a mountain to climb and we took it bit by bit," Arsenal manager Mikel Arteta told the BBC.

"When it's ugly and when it's difficult, that's what big teams do. We have to make it easier for ourselves. But this is the Premier League. There is nothing like sharing those great moments with your people."

Manchester City's earlier 2-0 defeat of Newcastle United had ratcheted up the pressure on Arsenal, cutting their lead to two points, and when relegation-threatened Bournemouth's Philip Billing scored after nine seconds the hosts were stunned.

Timed at 9.11 seconds, Billing's close-range finish from an audacious attack straight from the kickoff was the second-quickest goal ever scored in the Premier League era.

Shane Long's effort 7.69 seconds after kickoff for Southampton against Watford in 2019 is the quickest.

Arsenal dominated possession and were denied by a combination of visiting keeper Neto and some last-ditch defending, although Bournemouth had their moments too with home keeper Aaron Ramsdale making a crucial save from Dango Ouattara who should have made it 2-0.

Bournemouth rode their luck, and their fans were in dreamland when Marcos Senesi rose unmarked to head in a second for his side just before the hour mark. It looked as though Arsenal's grip on top spot might just be coming loose.

Then began an Arsenal comeback that could prove pivotal in their hopes of winning the Premier League title for the first time since 2004.

Thomas Partey prodded a shot past Neto shortly after the hour mark, and eight minutes later substitute Ben White's volley crossed the line despite Neto's desperate dive.

Arsenal laid siege to the Bournemouth goal as the clock ticked down but it appeared the visitors had held on for a precious point in their own desperate fight against relegation.

But substitute Nelson supplied a dramatic sucker-punch to spark incredible celebrations on and off the pitch and re-establish Arsenal's five-point lead over City.

Arteta's side have 63 points from 26 games with City on 58. Bournemouth are in 19th place with 21 points.

It felt like one of those afternoons that defines title races, but Arteta offered a dose of realism.

"It's just another game, another three points," he said, although he might have had a tough time selling that line to the jubilant fans streaming out of the stadium afterwards.

It was hard on Bournemouth's players and boss Gary O'Neil. "We gave it our best and came up a few seconds short," he said.