Two injury-time goals from Katie McCabe and Alessia Russo snatched all three points for the Gunners as Jonas Eidevall's side beat Aston Villa at the Emirates Stadium on Sunday.
In front of a crowd of 35,829, the Gunners lined up for this game in their usual 3-4-3 formation, with summer signing Russo up front for her third consecutive start since signing for the club from title rivals Manchester United.
The England striker immediately looked to have an impact and closed down the onrushing Daphne van Domselaar in the Aston Villa goal, who attempted to play out from the back in the early stages.
But despite the early pressure from Russo and the Arsenal forward line, the Gunners struggled to make their mark and were frustrated by a stubborn Villa defensive unit for the majority of the first half.
The first chance of the game fell to Russo, however, as she failed to react to van Domselaar's error when she spilled the ball from a Caitlin Foord cross, but Scottish centre-half Rachel Corsie clawed the ball away from danger before Russo or McCabe had the chance to make a connection.
Just a few minutes later, the away side opened the scoring against the run of play as the ball came into the Arsenal box from a Villa corner, with midfielder Mayumi Pacheco rising highest to head home as Carla Ward's side took a shock lead at the Emirates.
As loud groans rang around the Emirates, Eidevall and his side looked dejected, and captain Kim Little decided it was time for a team huddle.
The home side continued to offer little in Villa's half and found it tricky to break down a resilient opponent, who looked well drilled for this game. As half-time beckoned, the Gunners huffed and puffed, nearly finding the net as Russo headed back across goal, but nobody arrived to tap the ball home.
As the second half kicked off, Arsenal looked to put pressure on the Villa full-backs as Foord and McCabe began to take control of the wide areas.
Fresh from signing her new contract with the club just weeks earlier, McCabe cut a frustrated figure as her dynamism down the right side failed to result in anything of note, largely due to the efforts of the excellent Danielle Turner.
Russo then had her first proper chance of the match as her well-timed volley struck the face of Corsie, who received treatment after she had stayed down. Despite the clear intent from the Gunners, seemingly straight-forward passes failed to reach their target on numerous occasions, and nearly every cross was headed away by the Villa defence.
Substitute Cloe Lacasse then made an immediate impact as she carried the ball down the right-hand touchline, releasing it to Noelle Maritz, whose cross reached Foord.
The Australian turned away from her marker and poked the ball towards goal, wheeling away in celebration, only to see her effort strike the post. Russo attempted to convert the rebound, but her outstretched leg pushed the ball straight into the arms of van Domselaar.
Beth Mead came on in the 86th minute for her first appearance in over a year, but it was club captain McCabe who was the hero as she slammed home a brilliant equaliser in the 92nd minute to spare Eidevall's blushes.
Just moments after the restart, the Gunners secured all three points in incredible, late fashion.
Mead held the ball up well on the edge of the box and laid it off to Russo, who squeezed a superb effort past van Domselaar to break Aston Villa hearts.
The Emirates erupted with joy, and Eidevall and his coaching staff jumped up in celebration. It was too late for Villa to salvage anything from the game, however, despite the 12 added minutes, as Arsenal emerged victorious.
Eidevall's side travel to Bristol City in a week's time (October 22, 6.45pm), before hosting Manchester City on November 5, with the Gunners boss looking to build on their stunning win.