Ange Postecoglou believes Tottenham’s 3-2 defeat to Brighton is the worst of his tenure as head coach.

Spurs were cruising to victory at the halfway point of Sunday’s clash at the Amex Stadium thanks to goals from Brennan Johnson and James Maddison. But somehow, they left empty-handed.

Welbeck completed the Brighton comeback in the 66th minuteGetty

Spurs threw away a 2-0 lead with a dismal second-half showingGetty

Yankuba Minteh, Georginio Rutter and Danny Welbeck scored within 21 minutes of the restart to seal a stunning Brighton turnaround.

Defeat is Postecoglou’s 17th from 51 matches across all competitions since he took charge last summer.

The scoreline was not as bad as their heaviest loss, 4-0 away at Newcastle last season, but he’ll be keen to forget this one in a hurry.

“Yeah, that’s disappointing,” he told Sky Sports following a contrasting performance level in the first and second halves of the match.

“I’m frustrated, I’m absolutely gutted with that, it’s probably the worst defeat we’ve had since I’ve been here.

“Unacceptable second half, we weren’t anywhere near where we should be, maybe we just got carried away with how we were going.”

When asked if there was a problem with his side’s mentality, he said: “Yeah I think so.

“Second half, I just don’t think… we kind of accepted our fate, which is a bit hard to understand because we haven’t done that since I’ve been here, we’ve usually followed through everything.

“But when you don’t, you pay a price and we paid the price.”

Spurs have also made unwanted history with Sunday’s result as they are the first ever Premier League side to lose ten matches when taking a 2-0 lead.

Postecoglou cut a furious figure during his post-match interview@SkySportsPL X

He said Spurs’ second-half performance was ‘unacceptable’Getty

The record-breaking result left former Spurs star Dimitar Berbatov dumbfounded.

“Is it possible Spurs were telling themselves at half-time they won the game?” Berbatov asked the rest of the panel on Sky Sports.

“Is that also a possibility? Coming from us [Berbatov, Les Ferdinand and Steve Sidwell] who used to play the game.

“Maybe they were thinking it was going to be easy in the second half.

“They maybe underestimated Brighton a bit and that was probably the mistake as well, as in the second half Spurs weren’t there.

“From the first half, it was gone, and we were watching here in disbelief, like what is going on?”

Although the result against Brighton is only the first time this has happened under Postecoglou, fans will undoubtedly be worried.

Postecoglou’s men have already experienced a few setbacks this seasonGetty

They have lost for the third time in the Premier League this season, with Newcastle and north London rivals Arsenal the other teams to get the better of them.

In comparison, Spurs were unbeaten at this stage of last season and didn’t fall to defeat until November when they lost 4-2 to Chelsea.

They sit ninth in the table on ten points and will now have to wait two weeks to provide a response due to the international break.

Spurs will host London rivals West Ham on Saturday 19 October, live on talkSPORT, in a bid to revive their chances of European qualification.