A dramatic and agonisingly late West Ham comeback cost the Seagulls all three points at the Chigwell Construction Stadium in the WSL on Sunday.
With just nine minutes of the game remaining, memorable strikes from Kiko Seike and Manuela Vanegas looked set to make it back-to-back away victories for the Albion.
Yet, incredibly, the Hammers scored three times in the closing stages to made it back-to-back defeats for interim Chris Roberts' side.
Albion, looking to bounce back from last week's loss against London City Lionesses, showed their intentions clear by going close as early as the eighth minute when Madison Haley found space inside the box only to see her curling left-foot effort sail narrowly wide.
Delight for Kiko Seike and her teammates after she put Albion in front. 📷Kyle Hemsley
In what was an even opening, the Hammers looked dangerous on the break without causing the Albion rearguard too many problems. Indeed, the closest the hosts came to troubling Chiamaka Nnadozie was through a Shekeira Martinez effort that flashed wide of the goal, while Eva Nystrom also connected with an inswinging corner but her header was comfortably held by the Albion keeper.
West Ham started to apply more more pressure as the half wore while Albion responded when Maisie Symonds pounced on a poor ball out of defence, only to see her low drive comfortably saved by Kinga Szemik.
A Charlie Rule slip almost let in the Hammers soon after but, again, Nnadozie was equal to Martinez's close-range effort.
The Albion No .1 was also called into action six minutes before the break, spectacularly tipping a 25-yard free-kick from Viviane Asseyi onto the bar and away for a corner.
Madison Haley, who had an early penalty appeal turned down, is brought down. 📷Kyle Hemsley
It proved to be a pivotal moment as in the next passage of play, a long pass forward from Moeka Minami was met by compatriot Seike, who superbly lifting the ball over a stranded Szemik from outside of the box.
The hosts started the second half brightly, with Asseyi causing problems down the left flank but it was the Seagulls who landed what looked to be an all-important sucker-punch in the 63rd minute when Vanegas showed real determination to cut out a Hammers break. The full-back then burst forward, playing a neat one-two with Haley, before firing home an unstoppable shot from inside the box.
Assayi should have done better with a close-range header while Albion sub Tvedten had an effort saved by the feet of Szemik.
West Ham keeper Kinga Szemik can't believe it after she was lobbed by Kiko Seike. 📷Kyle Hemsley
The Hammers then got back into the game in rather fortuitous circumstances when Ffion Morgan's deep cross from the right sailed over a back-peddling Nnadozie and the ball nestled into the back of the net.
It set up a frenetic finale and the Hammer equalised just four minutes later when Nnadozie raced out of her box to close down Martinez, who was attempting to latch onto a long ball from Katie Zelem. Unfortunately, the Albion keeper failed to connect with the ball, leaving the West Ham forward free to guide the ball into an empty net.
With the tails up, Asseyi grabbed what had looked like an unlikely winner in the 91st minute when she bundled home after Nnadozie had made a good close-range save, leaving the Seagulls shellshocked at what had taken place.
Albion: Nnadozie, Rule (60 McLaughlan), Minami, Vanegas, Olislagers (90 Camacho), Noordam, Symonds, Cankovic, Kafaji (60 Tvedten), Seike, Haley.
Subs not used: Poulter, Baggaley, Rayner, Hayes, Camacho, Tsunoda, McEwen.