Leandro Trossard’s 83rd minute goal reestablished the Gunners’ five-point lead over Manchester City.
But West Ham had an equaliser deep into stoppage time ruled out after a VAR review for a foul on goalkeeper David Raya before Callum Wilson fired home.
Victories over already-relegated Burnley and Crystal Palace will end Arsenal’s long wait to be champions of England after the club sealed their place in the Champions League final with victory over Atletico Madrid in midweek
But there was another huge moment to come as Raya flapped at a corner under pressure from Pablo and Wilson drilled in the rebound.
After a lengthy VAR review, the referee deemed the Portuguese forward had impeded the Arsenal goalkeeper.
If City fail to beat Palace at home on Wednesday, Arsenal could seal the title on home soil against Burnley on May 18.
City kept the pressure on the Gunners at the top with a 3-0 win over Brentford, thanks to goals from Jeremy Doku, Erling Haaland and Omar Marmoush.
Elsewhere, Liverpool were booed off after a 1-1 draw against struggling Chelsea and Manchester United played out a 0-0 draw at Sunderland.
Bournemouth’s 1-0 win over Fulham cut Liverpool’s lead over the sixth-placed Cherries to four points with two games remaining while Chelsea can no longer mathematically finish in the top five and remain in ninth.
Aston Villa left the battle for a place in the top five open after a costly 2-2 draw at Burnley yesterday.
Unai Emery’s men booked their place in the Europa League final on Thursday with a 4-0 demolition of Nottingham Forest, but suffered a European hangover at Turf Moor.
Villa extend their lead over sixth-placed Bournemouth to four points and move six ahead of Brighton in the battle for Champions League qualification.
However, they face a tough end to the campaign with matches against Liverpool and Manchester City either side of the final against Freiburg in Istanbul.
Everton’s bid for a place in Europe next season suffered from again failing to hold onto a lead in a 2-2 draw at Crystal Palace while Elliott Anderson struck late against his former club Newcastle to secure a 1-1 draw and also guarantee survival for Nottingham Forest.
Brighton climbed to seventh, just two points behind Bournemouth, with a 3-0 win over Wolves.
Sixth-place could still secure a place in the Champions League if Villa finish fifth and win the Europa League final against Freiburg later this month.