Everton led Bournemouth 2-0 by the 87th minute and inexplicably lost 3-2 to remain rooted to the bottom of the Premier League.
Everton's dreams of a much-needed first win of the season were shattered in the cruelest of fashions.
Everton led 2-0 with just minutes to go, courtesy of Michael Keane and Dominic Calvert-Lewin's strikes.
Sean Dyche's side looked home and dry but then, disaster struck. Antoine Semenyo's late goal sparked a stunning Bournemouth comeback, with Lewis Cook and Luis Sinisterra netting in stoppage time to snatch a 3-2 win.
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Dyche was left fuming, saying:
"I've had a few [defeats] down my years as a player, coach, manager, but this is the most frustrating because to dominate a game for so long and come out of it without something at least is incredibly frustrating.
"They had one shot on target before their goal and we just threw the game away. Just from not doing the hard yards and the basics, win tackles, win headers, and see the game through. We don't do that and they chip it forward like they had done all day - which we dealt with all day - and our body language said it all."
Everton remain rooted to the bottom of the table with three defeats from their opening three games and the pressure is now firmly on Dyche to turn things around after the international break.