Reiss Nelson's last-gasp winner saw Arsenal fight back from two goals down to beat lowly Bournemouth and maintain their five-point lead at the top of the Premier League.With Manchester City beating Newcastle earlier in the day, Mikel Arteta’s leaders had to scramble from behind, substitute Nelson sealing a remarkable three points with a fine winner.The struggling Cherries had only won away at Nottingham Forest and Wolves this season but raced into an early lead as Philip Billing scored the second-fastest goal in Premier League history.They doubled their advantage as Marcos Senesi headed home after the interval before the Gunners finally rallied.Fit-again Thomas Partey got one back before Ben White’s maiden goal for Arsenal – and his first in 955 days – had them level with 20 minutes to go.They would need all of that time, and more, as Nelson – on his first league appearance since 12 November – struck with almost the last kick of six minutes of stoppage time to break Bournemouth hearts and lift the roof off the Emirates Stadium.The home fans had been stunned into silence earlier in the afternoon as Billing tapped home with just 9.11 seconds on the clock, turning in a Dango Ouattara cross with the home defence caught cold.Arsenal looked to respond immediately but Neto made a fine low stop from Martin Odegaard before leaping to his feet to keep out Bukayo Saka’s effort on the rebound.Bournemouth could have had a second as they broke at Arsenal, who were now dominating possession, former Cherries goalkeeper Aaron Ramsdale making a crucial save from Ouattara.The hosts were forced into an early change as Leandro Trossard limped off to be replaced by Emile Smith Rowe, with the game seemingly set as attack against defence.Gabrie