Chelsea needed extra-time and penalties to unconvincingly scrape past second-tier Norwich and progress in the FA Cup, with Swansea and Wigan also securing safe passage to round four.
Premier League champions Chelsea labored for much of the game before eventually finding a way past their plucky opponents via a penalty shootout, despite a brilliant performance from the visitors.
The visitors grew more confident as the half went on, with Josh Murphy causing the Blues defence problems as the two teams went into the interval goalless.
Both sides hit the woodwork early on, with Danny Drinkwater striking the crossbar midway through the first half, and Nelson Oliveira latching onto an errant pass from Michy Batshuayi to crack a speculative effort onto the frame of the goal.
The Norwich resistance was finally broken 10 minutes after the break, when Batshuayi met a Kenedy cross and sidefooted home, to visible relief at Stamford Bridge.
The Belgian has been linked with a move away this month, and this will have done his case for selection no harm.
The Canaries stood firm under pressure to keep the scoreline at 1-0. With Norwich pushing for an equalizer, Jamal Lewis headed a Timm Klose cross past Willy Caballero in the fourth minute of stoppage time to stun the hosts and force extra time in west London.
Willian had a controversial penalty appeal turned down early in the extra period, with the Brazilian booked to compound his misery, despite Antonio Conte and the other players bemused as to why VAR was not employed, after its success at Leicester Tuesday.
Angus Gunn made two outstanding saves to deny Alvaro Morata and Willian as the visitors tried to recover from their anguish at the referee's decision.
The home side were reduced to nine men as Pedro was sent off for a second yellow card, before Morata got two bookings in quick succession for diving and dissent afterwards.
The game went to spot-kicks, with the Blues finally prevailing after scoring all five penalties. Eden Hazard scored the decisive penalty after Nelson Oliveira missed the opening chance for Norwich. It was an enthralling encounter that left serious questions about Antonio Conte's squad despite registering a first win of 2018.
Elsewhere, bottom-of-the-table Swansea gained a shred of momentum in a surprising 2-1 win over Championship leaders Wolves.
The home side took an early lead through one of the goals of the round from Jordan Ayew. The Ghanaian weaved through the Wolves defense, twisting and turning in the box before sidefooting past Will Norris.
The in-form visitors, holding a double-digit lead in the Championship, offered little by way of a response as Carlos Carvahal's men looked good value for their half-time lead.
Both sides started the second half conservatively, with neither side making a move.
With 25 minutes remaining, Nuno Santo brought on Atletico loanee Diogo Jota, who intervened almost immediately, controlling the ball smartly before rifling in at the near post to bring the scores level.
Wolves were unable to hold on for long, with Wilfried Bony sliding in from Tom Carroll's cross two minutes later to restore the Swans' advantage.
Despite sustained Wolves pressure, the home side held on for a much-needed win to book a trip to League Two Notts County next weekend.
In the final game of the night, League One leaders Wigan Athletic went through to round four with a memorable 3-0 victory over top-flight Bournemouth. Eddie Howe decided against risking Junior Stanislas and Josh King on their return from injury, and paid the price as the third-tier side produced a brilliant performance to overwhelm the weakened Cherries.
Skipper Sam Morsy put the home side in front after nine minutes, stroking home after Will Grigg's effort was well saved by Artur Boruc.
It was nothing more than they deserved, with the 2013 winners starting the game brightly against their more established visitors, who beat Arsenal 2-1 at the weekend.
The hosts grew in confidence as the half went on and took a comfortable lead at the interval.Two goals in three minutes from substitute Dan Burn and Callum Elder after the break sent the DW Stadium into raptures and left the away side three goals down with 15 minutes left to play.
It was purely academic from there, with the hosts seeing out the rest of the match to seal a famous win against Premier League opposition.
The Latics will host another top-flight side in the fourth round in West Ham, who saw off Shrewsbury yesterday after extra time.