Record FA Cup winners Arsenal were knocked out of the competition after a 1-0 defeat to Championship side Nottingham Forest.
Lewis Grabban’s 83rd minute strike, converting Ryan Yates’ cross from close range, was enough to see Forest through against a lacklustre Gunners side.
Meanwhile, North London rivals Tottenham came from behind to avoid a huge upset by scoring three goals in the final 16 minutes to see off League One side Morecambe 3-1 at the Tottenham Hotspur Stadium.
Anthony O’Connor’s first-half goal had the visitors, 59 places below their hosts on the football ladder, dreaming of a famous win until quickfire goals from Harry Winks, Lucas Moura and Harry Kane sent Spurs through.
There was no cup upset at The Valley either as Charlton Athletic were dumped out 1-0 by Premier League strugglers Norwich City.
Milot Rashica’s late winner against the run of play in the 79th minute, after Charlton had dominated for large parts, saw the Canaries safely through.
It was a similar story for Leyton Orient as Tom Ince’s first-half goal and a late Tyrese Campbell strike earned Stoke City a 2-0 win over the O’s.
Ince netted three minutes from half-time and then provided the pass for substitute Campbell to settle the contest in the 89th minute.
Elsewhere, Manuel Lanzini and Jarrod Bowen were on the score sheet as West Ham United won an entertaining all-Premier League tie 2-0 against Leeds United at the London Stadium.
In Saturday’s action, Millwall were dumped out of the competition with a 2-1 defeat to South London rivals Crystal Palace at The Den.
Benik Afobe put the Lions ahead early on after former England international goalkeeper Jack Butland was caught trying to play out of the six-yard box.
However, Michael Olise struck a fine individual goal to equalise within a minute of the restart before Jean-Philippe Mateta (58) headed home what proved to be the winner in a fiery clash.
QPR avoided an upset as they saw off League One leaders Rotherham 8-7 on penalties, with keeper Jordan Archer saving two spot-kicks.
After a goalless 90 minutes, Michael Ihiekwe (98) put the Millers in front, but an equaliser from Lyndon Dykes (115) sent the tie to a shoot-out where the Hoops finally prevailed.
Elsewhere, substitute Harry Wilson struck in extra-time to give Fulham a 1-0 win at fellow Championship side Bristol City.
The midfielder’s inswinging cross from the right in the 105th minute was missed by attackers and defenders alike and crept inside goalkeeper Max O’Leary’s far post.
Meanwhile AFC Wimbledon, who caused probably the biggest upset of them all when they beat Liverpool in the 1988 final, for once found themselves on the wrong end of a cup surprise.
Goals from Tyrone Marsh and Adrian Clifton secured a 2-0 victory for National League Boreham Wood and one of the shocks of the round against the Dons.
There was no such drama for Brentford though as Bryan Mbeumo came off the bench to score a second-half hat-trick as the Bees ran out 4-1 winners at Port Vale.
Marcus Forss (26) put Thomas Frank’s side in front with Mbeumo (66) adding a second shortly after coming on.
Although Kian Harratt (70) pulled a goal back for Vale, Mbeumo made it 3-1 with 14 minutes left before slotting home a late penalty.
In Saturday’s late kick-offs, Chelsea coasted to a 5-1 win over National League Chesterfield at Stamford Bridge.
Timo Werner (5) gave the Blues an early lead, with Callum Hudson-Odoi (18), Romelu Lukaku (20) and Andreas Christensen (39) putting the tie to bed before half-time.
Christian Pulisic (55) slotted a fifth from the penalty spot before Chesterfield supporters were given a moment to savour when Akwasi Asante (80) stabbed in a late consolation.
FOURTH ROUND DRAW (LONDON TIES)
Crystal Palace vs Hartlepool
Peterborough vs QPR
Chelsea vs Plymouth
Everton vs Brentford
Kidderminster vs West Ham United
Tottenham vs Brighton
Manchester City vs Fulham
Ties to be played weekend of 4 -6 February