Spurs were on course for a sixth consecutive victory in all competitions when Brennan Johnson and James Maddison struck before half-time to them 2-0 up at Amex Stadium.

That made it six goals in six matches for Johnson, but the Seagulls were transformed after the break with Yankuba Minteh able to reduce the deficit in the 48th minute.

The impressive Georginio Rutter levelled 10 minutes later with a fine finish before ex-Arsenal forward Danny Welbeck completed the comeback when he headed home what proved the winner after 66 minutes.

While Tottenham produced a dominant first-half display, they were second-best after and looked a shadow of the team which had entered this fixture after fine triumphs on the road at Manchester United and Ferencvaros.

"That's probably the most disappointing loss I've had since I've been here, in terms of the way we went about it and it's something I need to assess," Postecoglou reflected after his 51st match in charge of Spurs.

"We didn't do what you need to do at this level, it's kind of non-negotiable. We just weren't competitive.

"We didn't win our duels, we lacked intensity, we didn't deliver the things you need to at this level, the basics of the game, and paid the price for it.

"Wherever it comes from, it doesn't really matter, it's irrelevant. It's unacceptable at the end of the day.

"You can kind of understand that you're not going to win every game, but there's the manner you lose games.

"And that's the first time since I've been here that we've lost the game in that manner. And like I said, unacceptable.

"There's a lot I can do about it. That's why I'm in the role. If I couldn't do anything about it, I'd get somebody else to sit here."

He added: "It's a terrible loss for us, as bad as it gets, and there's only one way to fix it and that's my responsibility.

"(It is) probably the worst defeat since I've been here."

Spurs started like a train at Brighton with Timo Werner, Dejan Kulusevski and Maddison unable to make the most of openings inside the first 10 minutes.

The visitors did lead after 23 minutes when Dominic Solanke slipped through Johnson, who kept up his hot streak with a fine left-footed finish.

After Welbeck sent an effort wide soon after, Tottenham went 2-0 up when Werner cut back for Maddison and his low strike went through the hands of Bart Verbruggen.

Johnson could have added a third before the break, but Brighton boss Fabian Hurzeler sent on Pervis Estupinan at half-time and the left-back immediately combined with Kaoru Mitoma to set up Minteh to lash home.

The 48th-minute effort occurred after a mistake by Destiny Udogie and the Seagulls levelled when Mitoma played in Rutter to drill into the bottom corner with 58 minutes on the clock.

Welbeck completed the comeback after fine wing-play by Rutter, who got the better of Udogie and Rodrigo Bentancur to set up former England international Welbeck to head in from close range after 66 minutes.

Hurzeler played down his role in the comeback, saying: "I am really proud how the team reacted because also at half-time, they take the responsibility, they showed character, they showed personality and the reaction was great in the second half.

"We have great characters in the team. In the end, it is my responsibility to help the team to stay positive, to find the right words, to find the right solutions, but to be honest it was the players' game in the second half.

"They deserved it, they worked hard, they were more ruthless, they were more intense and they worked hard for the goals."

READ MORE: Pep Guardiola grateful as Ederson stays at Man City amid Saudi interest

EMIRATES-STADIUM

Arsenal return to winning ways with Brighton rout

Mikel Arteta hails Arsenal following impressive Champions League return

Editors Pick