Brennan Johnson's well-taken opener marked his sixth goal in as many games across all competitions before James Maddison's first-half finish had Spurs leading 2-0 at the break.

However, Fabian Hurzeler's hosts managed a remarkable turnaround as Georginio Rutter levelled after Yankuba Minteh's strike, before Danny Welbeck completed a remarkable turnaround just past the hour.

It was just the second time that Tottenham lost a Premier League game it led by two goals in its past 166 matches, and Postecoglou fumed at the full-time whistle.

The Tottenham manager said: "Disappointing, frustrated and absolutely gutted with that. It's the worst defeat since I've been here.

"Unacceptable second half, and nowhere near where we should be. We got carried away with how we were going.

"We kind of accepted our fate [in the second half] and it is hard to understand as we've not done that while I've been here. We paid the price.

"The problem is we are travelling along too smoothly, football and life will trip you up if you get too far ahead of yourself."

The result also marked the 10th time that Tottenham has lost a Premier League game in which it led by two or more goals, becoming the first club to hit double figures for this unwanted record.

Postecoglou insisted finding a solution remains solely on his shoulders.

"There is no message," the Australian said when asked what he would tell his players. "It is a terrible loss for us, as bad as it gets. There is only one way to fix it and that's my responsibility.

"We lost all our duels and if you're not competitive it is not going to work; we were not competitive.

"They all go on international duty the majority of them, they will process it individually and I will process it when everyone gets back."