Jamie Carragher has labelled Tottenham "disgraceful" and captain Hugo Lloris said he was "embarrassed" after they shipped five goals in the opening 21 minutes against Newcastle.
Jacob Murphy opened the scoring after just two minutes before further strikes from Joelinton (8), a second from Murphy and an Alexander Isak double produced an astonishing scoreline at St James' Park.
Leading 5-0 within 21 minutes, it was the second-earliest a side has done so in Premier League history, after Man City against Watford in September 2019 - after just 18 minutes.
Former Tottenham defender Danny Rose, watching in disbelief on Sky Sports, exclaimed: "All I've been thinking of in that first half is, how am I unemployed?"
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Carragher wrote on social media: "Newcastle are brilliant, they have been all season. Tottenham are a disgrace! How have they gone to a back four for the first time this season, with [Pedro] Porro a full-back that can't defend and [Ivan] Perisic who is a winger? Get a proper manager in right now, not Conte's mate."
Former Newcastle midfielder Kieron Dyer told Sky Sports: "I'm in disbelief. I thought Newcastle would win the game, but to be 5-0 up after 21 minutes is incredible.
"There was a lot made about Antonio Conte when he came out with his outburst, but this is why he did it. Everything he said has come true.
"Spurs cost the manager his job, they're that bad. The centre-halves have been poor, the full-backs haven't been up to it, the midfield has been poor - (Oliver) Skipp's the only one who's really tried in there.
"Spurs have let the fans down, they've let everyone associated with the club down and it took Stellini half an hour to move to five at the back. By then, it was all over."
Spurs eventually lost 6-1 and slip six points off the Champions League places having played a game more than Newcastle. With the humbling defeat coming only a week after their late loss at home to Bournemouth, their season has been plunged into crisis.
After the game, Spurs captain Hugo Lloris - who came off at half-time - apologised to the club's fans and described the defeat as "very embarrassing".
What Stellini said after the match
Tottenham boss Cristian Stellini, who was sacked on Monday and replaced by Ryan Mason, said to Sky Sports: "We were not prepared enough to play an important match. We have a good squad, but today no-one showed how good (they are).
"It was my responsibility to decide the system today and we decided to do it differently because we had many injured.
"It is my responsibility to take this type of decision, I took it and it was wrong.
"I have to take responsibility because after we changed system, the game was gone, we had to play better and we did. We scored and tried to fight, but it is very difficult to understand why the first 25 minutes were so bad."
Lloris: We could not fight, we could not react
Tottenham captain Hugo Lloris to Sky Sports:
"It's very embarrassing. The first thing is probably we should apologise to the fans who travelled, the fans who watched the game. Obviously we didn't show a great face today. We could not match the performance of the Newcastle players. We were late in all the aspects of the game. We completely missed the first part of the game. Obviously the second half is another story. It's really painful.
"It's not even about talking of tactics, it's just we could not fight. Newcastle had a great performance, they were very aggressive, very offensive. Every time they got the ball they were looking forward and, I don't know, it's difficult to assess and analyse the performance. The first thing was a lack of pride.
"To concede four goals in 20 minutes... you can get punched once, twice. But it was something strange, like we could not even react. We could not even bounce back into the game, into the performance. But Newcastle deserve a lot of credit. They started the game with power, they were very dynamic and they knew exactly what to do, with the ball and without the ball.
"We can try to find excuses and analyse the performance but the first thing is we miss the fight. In football, if you go on the pitch without the desire to show aggressiveness, to win duels, to win the battle it makes things very hard. Or you have to be very good with the ball technically and tactically. It was a big mess.
"We can't hide behind the club's problems. We are players, we are professional and every time we go onto the field we try to deliver the best but today there was too much lacking in all the aspects. Now there are two other games very difficult in the week and we have to bounce back."
Spurs' change in formation goes wrong
Prior to kick-off, former Spurs full-back Rose had told Sky Sports he was in favour of Stellini's switch to a back four following the late home defeat to Bournemouth.
"I'm happy they've gone to a back four," said Rose. "Some of the games I've watched, they've played with a back five and two defensive midfielders - so that's seven. With the goalkeeper, it's eight.
"But they were still conceding two goals each game. For me, that's not right. You're not defending properly. So, it's right they've gone with a back four and with a three in the midfield to match Newcastle.
"Once you win the midfield battle, that's half the battle won."
But Spurs lost every battle. Perisic and Porro - not recognised full-backs - were left horribly exposed as Newcastle ran riot in the opening 21 minutes.
Tottenham reverted to a back five by bringing Davinson Sanchez on after 23 minutes for Pape Sarr, but the damage had already been irrevocably inflicted.
Gary Neville was scathing of Porro's failure to make a tackle for Murphy's oppening goal. Cristian Romero was also not without blame.
At full-time, Redknapp was equally unimpressed with Romero for Murphy's first goal.
"Look at him, with his hands behind his back," he said. "This is as bad a piece of defending as you're ever likely to see. It's been in the game for a long time now but just defend properly and move your feet and block the ball. That summed it up and set the tempo for the whole game."
Tottenham played with a back four a couple of times under Conte, but very rarely. The last time was against Chelsea in January 2022.
Redknapp added: "They weren't quick enough and they weren't aggressive enough. Every single goal you can pinpoint from Tottenham's point of view, but you have to give Newcastle credit as well.
"Playing Porro and Perisic in the full-back positions, this wasn't the right time to experiment. Not the right place, and not the right time as they've played with a back three all season. You need to have recognised full-backs when you play a back four who understand the position.
"You've still got to do the basics well."
Spurs' crushing defeat in numbers
- Newcastle have won a Premier League game by a margin of 5+ goals for the first time since January 2011 vs West Ham (5-0), while Spurs have lost a Premier League game by a margin of 5+ goals for the first time since December 2013 vs Liverpool (0-5).
- Having won the reverse fixture in October, Newcastle have completed a league double against Spurs for the first time since 2015-16. The Magpies had failed to win this exact fixture in five successive seasons before today (D1 L4).
- Spurs have conceded nine goals across their last two Premier League matches, letting in three against Bournemouth in their previous game. It's the most goals they've conceded across two consecutive league games since May 2003 (9 - 5 vs Middlesbrough and 4 vs Blackburn).
- Spurs have both scored and conceded 50+ goals in the Premier League this season - they are only the fourth side to do within their first 32 games in a season, after QPR in 1994-95 (32nd game), Spurs themselves in 2007-08 (30th game) and Leeds United in 2020-21 (32nd game).