Newcastle's miserable season on the field sunk to a new low on Saturday as they were dumped out of the FA Cup 1-0 by third-tier Cambridge, while non-league sides Kidderminster and Boreham Wood also booked their places in the fourth round.
Chelsea scored four times in the first 40 minutes in a 5-1 demolition of Chesterfield, while Everton avoided another damaging defeat for manager Rafael Benitez as they needed extra-time to see off Hull 3-2.
England international Kieran Trippier made his debut as Newcastle's first signing since a controversial takeover by the Saudi sovereign wealth fund.
But the Magpies have still won only one match all season and were embarrassed by a side two divisions below them in front of a furious full house at St James' Park.
Joe Ironside scored the only goal 11 minutes into the second half as he swivelled to fire home from close range after a goalmouth scramble.
"It panned out how I dreamed about it last night," said Ironside who grew up idolising Newcastle's record goalscorer Alan Shearer.
"Shearer was my hero," he added. "Now I have scored the winner at St James' Park."
Newcastle had two goals ruled out and Joelinton was thwarted by a great save by Dimitar Mitov deep into stoppage time.
But they were shown no mercy by the disgruntled home fans at full-time as they now have to lift themselves to try and remain in the Premier League.
"I don't think there was anything wrong with our attitude, we just couldn't deliver the quality to score," said Newcastle manager Eddie Howe.
Sixth-tier Kidderminster overcame the 79 places separating them from Reading in the English football pyramid to beat the Championship side 2-1.
George Puscas put the Royals ahead at the Aggborough Stadium, but Sam Austin levelled before Amari Morgan-Smith struck the winner eight minutes from time.
The full-time whistle sparked a pitch invasion from fans of both sides with some angry Reading fans confronting their own manager Veljko Paunovic.
Boreham Wood also upset a side two divisions above them with a 2-0 win over AFC Wimbledon.
Goals from Tyrone Marsh and Adrian Clifton either side of half-time took the National League side into the fourth round for the first time.
But there was no such fairytale for non-league Chesterfield against the European champions at Stamford Bridge.
Timo Werner, Callum Hudson-Odoi, Andreas Christensen, Romelu Lukaku and Hakim Ziyech were on target as Chelsea's strength in depth shone through.
"We trust our players and we had to manage the load, to not overload the players with the next four games and the upcoming two weeks," said Chelsea boss Thomas Tuchel. "We started well and decided the game early."
Everton fell behind just a minute in at Hull to Tyler Smith's header, but bounced back to lead at half-time through Demarai Gray and Andre Gomes.
Ryan Longman equalised with a stunning strike and Hull nearly snatched the tie when Keane Lewis-Potter hit the post late on.
However, Andros Townsend's long-range effort ensured the Premier League side prevailed and eased the pressure on Benitez.
Holders Leicester saw off an injury crisis and a power cut at the King Power to thrash Watford 4-1 with Youri Tielemans, James Maddison, Harvey Barnes and Marc Albrighton on target.
Crystal Palace came from behind to beat Millwall 2-1 in a South London derby marred by the home fans booing when the Eagles took a knee before kick-off.
"We as a football club are against any kind of discrimination and of course this is not something we want to see on the field," said Palace manager Patrick Vieira.
Southampton survived playing for 90 minutes with 10 men to beat Swansea 3-2 after extra-time.
Brighton also had to come from a goal down to beat Championship opposition as they saw off West Brom 2-1 after extra-time.
Brentford thrashed Port Vale 4-1, but Burnley were the first top-flight side to bow out after a 2-1 home defeat to Huddersfield.