Birmingham City 1-2 Swansea City
Swansea City had to come from behind to record a win over their Championship opponents after Lee Novak hit yet another FA Cup goal early on.
Midway through the second half, though, Swansea turned the game on its head with two Wilfried Bony goals in the space of three minutes.
Bolton Wanderers 0-1 Cardiff City
A single second-half goal was enough for Ole Gunnar Solskjaer's new charges to see off the threat of Bolton Wanderers, as his good start to life as Cardiff City boss continued.
Frazier Richardson scored early on after the re-start, having only come on as a sub at half-time.
Huddersfield Town 0-1 Charlton Athletic
Charlton recorded a 1-0 win away from home by knocking out Huddersfield Town.
The result was something of an upset, with Charlton struggling near the foot of the Championship and with just two wins away from home all season. Simon Church scored the decisive goal on 55 minutes.
Port Vale 1-3 Brighton & Hove Albion
League One side Port Vale could not hold off Championship opposition in Brighton, as the Seagulls swept through by a 3-1 scoreline.
Rohan Ince and Chris Robertson traded strikes early on before a mis-hit cross from Solly March ended in the back of the net to restore Brighton's lead. Jon Obika scored the third late on.
Rochdale 1-2 Sheffield Wednesday
All the goals came in nine frantic minutes in the second half at Rochdale, with Championship side Sheffield Wednesday doing enough to squeeze through to the fifth round.
Joe Mattock and Oguchi Onyewu scored within six minutes of each other to put Wednesday in control before Michael Rose's long-range strike put the home side back in the game. A late red card for Mattock could have been costly, but the away side saw the game out.
Southampton 2-0 Yeovil Town
Premier League side Southampton easily saw off Championship strugglers Yeovil with a dominant display and a 2-0 win despite a much-changed side.
Guly do Prado ended his long scoreless streak from the penalty spot midway through the first half, before a first senior goal for Sam Gallagher sealed the win.
Southend United 0-2 Hull City
There was no upset at Southend, as the League Two promotion-chasing side were beaten by Premier League outfit Hull City.
A goalless first half gave way to two Matty Fryatt strikes in the second, with his brace coming in injury time at the end of the match.