Arsenal battled their way to a remarkable 4-2 win over Leicester at the Emirates after netting two stoppage-time goals.
Manchester City boss Pep Guardiola warned Mikel Arteta's men to prepare for a war as the rivalry between champions and contenders cranked up another notch prior to Saturday's Premier League fixture.
And, after seeing Newcastle battle to a draw against City at St James' Park, the Gunners knew a victory here would draw them level with the side they are attempting to dethrone.
Gabriel Martinelli and Leandro Trossard appeared to have sent them on their way. But James Justin's deflected header and brilliant volley after the interval – supported by an inspired Mads Hermansen in goal – left the hosts rocking.
However, Trossard's volley from a corner cannoned in off Wilfred Ndidi to win it for Arsenal in the fourth minute of added time before Kai Havertz struck a fourth as Arsenal joined City on 14 points after six matches.
For the first half, Arsenal looked at ease.
Bukayo Saka, handed the armband in Martin Odegaard's continued absence, pulled the strings for the hosts. It was his effort after 15 minutes which marked the first real test of the game.
Moments later, Saka was involved again, this time playing in Martinelli. The Brazilian had not scored since March 4 – a run of 19 matches – and his first touch was not good enough. It meant his shot was rushed and the ball went flying over.
However, Martinelli made amends four minutes later. The ball broke to Saka, who played in Jurrien Timber. The Dutch defender's pull-back was behind Martinelli, but, on the turn, he managed to nestle his shot into the bottom corner.
Jamie Vardy, who, perhaps rightly, felt he had been fouled by William Saliba in the build-up, and Leicester manager Steve Cooper were them both booked by referee Samuel Barrott following their respective protests.
Arsenal had dominated and Trossard gave them a deserved two-goal advantage at the interval when he converted Martinelli's cross in the first minute of first-half stoppage time.
Arsenal might have expected a comfortable second period, but Leicester had other ideas.
Vardy was fouled by Saliba seconds after the restart and Facundo Buonanotte's resulting free-kick was met by Justin, whose header flicked off Havertz's shoulder and past a wrong-footed David Raya.
Arsenal set about restoring breathing space and Hermansen produced a fine double save to deny Gabriel and then Riccardo Calafiori, with Timber blazing over.
Moments later, Saka's blocked shot fell into the path of Trossard, but his poked effort hit a post.
While Arsenal's advantage stood at just one goal, Leicester always had a chance and Buonanotte looked the most likely.
He hit the side-netting and then fired a shot down Raya's throat. The warning signs were there and in the 62nd minute Leicester were level after Justin superbly volleyed home Ndidi's cross.
A shell-shocked Arsenal went in search of a winner and Havertz's turn and volley at close range was superbly saved by Hermansen.
With 20 minutes left, Hermansen's dreadful pass fell straight to Declan Rice on the edge of the area and Trossard looked certain to score, only for the Leicester keeper to atone for his mistake with another fine save.
Ethan Nwaneri, the 17-year-old who scored a double against Bolton in midweek, looked as though he might have won it, only to see Hermansen thwart his effort. The Danish keeper was involved again from the ensuing corner when he palmed Calafiori's header over.
The game looked to be heading for a draw, but seven minutes of injury time provided Arsenal with hope and Trossard's side-footed volley from a corner hit Ndidi and past a helpless Hermansen.
Cue wild scenes at the Emirates, with Havertz then scoring a fourth to complete the win in the ninth minute of time added on.
