United and Hammers knocked out
Liverpool and Chelsea made the FA Cup fourth round on Sunday, but Nottingham Forest thrashed West Ham before Swansea shocked Manchester United.
Swansea inflicted more Old Trafford misery on United as they saw off the 10-man Red Devils 2-1.
Javier Hernandez cancelled out Wayne Routledge's opener at Old Trafford, but the game turned in the Swans' favour when Fabio was shown a straight red card 10 minutes from time.
The visitors were able to make their numerical advantage count as Wilfried Bony powered home a dramatic late header to help Michael Laudrup's men claim a notable scalp.
Sam Allardyce, meanwhile, faces fresh questions over his future as West Ham manager as an unrecognisable side were routed by second-tier Nottingham Forest in the third round of the FA Cup.
The Sky Bet Championship side's emphatic 5-0 win - courtesy of Djamel Abdoun's cheeky 'Panenka' penalty, Jamie Paterson's second-half hat-trick and Andy Reid's late finish - might go down in some quarters as a cup upset but once the team-sheets were announced the bookmakers had already installed the hosts as favourites.
Allardyce, with injury and suspension problems and a Capital One Cup semi-final in midweek, handed out a total of five debuts, three from the start and two more off the bench, among nine changes to his team.
It was a gamble that backfired horribly as the relegation-battling Hammers simply had their confidence further assaulted by lower-league opposition.
John Obi Mikel was an unlikely goalscorer to set Chelsea on their way to a 2-0 FA Cup third-round win at Derby which featured another diving incident.
The Rams had won 10 and lost just two of their prior 15 games under former England boss Steve McClaren and proved difficult for Jose Mourinho's men to break down at the iPro Stadium.
But Mikel headed in his fourth Chelsea goal on his 300th appearance after 66 minutes and Oscar added a second soon afterwards.
Much-maligned forward Iago Aspas scored his first Liverpool goal to help his club into the fourth round of the FA Cup but it was far from an easy 2-0 victory over Oldham.
The 26-year-old summer signing from Celta Vigo has endured a difficult start to his Anfield career and never looked comfortable in the Premier League.
Wearing the number nine shirt for Liverpool carries significant history and expectation considering the greats who have graced it in the past.
But Aspas was handed the responsibility of leading the line with 20-goal striker Luis Suarez rested and he eventually delivered with a decent strike 10 minutes after half-time.
James Tarkowski's late own goal, diverting in Raheem Sterling's shot, gave Liverpool the cushion they needed - especially as they were down to 10 men after Daniel Agger was forced off injured with three substitutions already made.
There was to be no fairytale repeat of Oldham's fourth-round victory over the Reds last January and Liverpool can now look forward to a trip to either Bournemouth or Burton Albion.
Beleaguered Gus Poyet was handed a boost as Sunderland eased past League One Carlisle to book their place in the FA Cup fourth round.
The relegation-haunted Black Cats headed in at 1-1 at half-time after Matty Robson had cancelled out Adam Johnson's fine free-kick.
However, Sean O'Hanlon's own goal and a late strike from substitute El-Hadji Ba meant it ended 3-1 to the hosts, killing off any hope of an upset for the 5,631 travelling fans among a crowd of 21,973 and securing a fourth round home tie against either Kidderminster or Peterborough for Poyet's men.
Plymouth will fancy their chances of causing an upset in a richly-deserved replay after they stormed back from two goals down to force a 2-2 draw in a thrilling FA Cup tie at Port Vale.
The visitors should have taken a 13th-minute lead when Tope Obadeyi fired a close-range shot against a post when it looked easier to score.
And Vale made them pay just two minutes later with the in-form Gavin Tomlin scoring for the fourth successive game.
Jennison Myrie-Williams curled over a free-kick from the left and Tomlin guided a 12-yard header low inside Jake Cole's left-hand post.
Plymouth had a mountain to climb when Tom Pope buried a 10-yard header from Doug Loft's left-wing cross in the 36th minute.
But they were right back in a pulsating clash six minutes after the break when Reuben Reid rolled the ball into an unguarded net from 12 yards after fine work by Durrell Berry and Lewis Alessandra.
And Alessandra also played the vital pass before substitute Ben Purrington squeezed a low left-foot shot inside Chris Neal's left-hand post from the corner of the six-yard box for a 73rd-minute equaliser.
It was all Plymouth in the closing stages and Andres Gurrieri was inches away from a winner in the last minute of normal time when his 20-yard shot crashed against Neal's right-hand post.