If Arsenal win the Premier League this season then their win away to West Ham United will be remembered as a pivotal moment in the season after late drama in London.
Both of these teams are fighting desperately, one for the title and it was the visitors who had the first big chance of the game when Leandro Trossard had a headed effort from a corner that Mads Hermansen pushed onto the crossbar.
Then only some last-ditch defending denied Riccardo Calafiori after Declan Rice's free-kick delivery.
Arsenal have had to rely on David Raya's saves at times this season and he produced some top class saves to stop the Hammers. First, keeping out Taty Castellanos' diving header just before the break and then denying Mateus Fernandes in the second half for what was a golden chance for the hosts.
That save to deny Fernandes was crucial as just a few minutes later, the Gunners took the lead after good work from substitute Martin Odegaard to find Trossard. The Belgian's shot took a deflection that made sure Hermansen couldn't get to it which gave Arsenal the lead in the 83rd minute.
West Ham put pressure on late on to try and get an equaliser and briefly thought they had got one in the fourth minute of stoppage time.
It came from a corner from the right that had the typical pushing a shoving that Arsenal have helped make standard in the Premier League. David Raya flapped at the ball under pressure with the ball coming out to Callum Wilson who fired an effort that crossed the line before being cleared.
VAR intervened though and directed Chris Kavanagh to watch the replay. Raya was certainly being impeded by Pablo Felipe.
But was it a clear and obvious error? And was it any different from numerous goals that have been given this season? Those questions will no doubt be debated for a long time but Kavanagh eventually decided to rule the goal out with Arsenal then holding on to claim the points.
Incidents: The story of the match
West Ham Official Line-ups:
Mads Hermansen, Aaron Wan-Bissaka, Kostas Mavropanos, Jean-Clair Todibo, Axel Disasi, El Hadji Diouf, Tomás Soucek, Mateus Fernandes, Crys Summerville, Jarrod Bowen, Taty Castellanos
Arsenal Official Line-ups:
David Raya, Ben White, Gabriel Magalhães, William Saliba, Riccardo Calafiori, Myles Lewis-Skelly, Declan Rice, Bukayo Saka, Viktor Gyökeres, Eberechi Eze, Leandro Trossard
1':
The match begins
Arsenal takes the lead 1-0 with Leandro Trossard scoring from the center of the box into the right corner, assisted by Martin Ødegaard.
83':
GOAL Arsenal: Leandro Trossard (Arsenal) scores!
Leandro Trossard scores goal number 6 in the competition (30 matches) Leandro Trossard scores goal number 37 for his team (173 matches)
The match is now 1-1 as Callum Wilson scores for West Ham United with a left-footed shot from the center of the box after a corner.
998':
The referee whistles for the end of the match
