The nine-men Swans bowed out of the FA Cup during a 3-1 defeat at Blackburn Rovers.
Garry Monk's side has been reduced to ten men after just six minutes as referee Craig Pawson showed Kyle Bartley a red card for bringing down Josh King.
But, despite their man disadvantage, they took the lead at Ewood Park thanks to Gylfi Sigurdsson's stunning 25-yard strike.
It lasted just two minutes, however, as Chris Taylor fired past Lukasz Fabianski from close range after Tom Cairney had nodded down Markus Olsson's cross.
Blackburn would go on to book their spot in the fifth round as sub Rudy Gestede poked home following a corner and Craig Conway's shot squirmed under Fabianski late on.
And things got worse for the Swans when referee Pawson dismissed Sigurdsson in added-on time following his challenge on Taylor.
The Swans made five changes to the starting line-up.
From the league defeat to Chelsea last time out, Garry Monk made three changes in defence as Angel Rangel - who captained the side - Kyle Bartley and Jordi Amat returned to action.
Jonjo Shelvey made his first appearance following a four-match ban while Modou Barrow - who scored in the 6-2 win over Tranmere in the last round - made his second start in the competition.
New signing Kyle Naughton, who joined from Tottenham Hotspur on Thursday, was included amongst the substitutes along with Jefferson Montero, who had recovered from a hamstring injury.
Captain Ashley Williams and Wayne Routledge both missed out through injury while Ki Sung-Yueng remained on international duty with South Korea at the Asian Cup.
Simon Eastwood, Adam Henley, Matt Kilgallon, Jason Lowe (capt), Josh King (Rudy Gestede, 59), Tom Cairney, Markus Olsson, Lee Williamson (David Dunn, 40; Jordan Rhodes, 76), Chris Taylor, Shane Duffy, Craig Conway.
Jason Steele, Ben Marshall, Grant Hanley, Chris Brown.
Lukasz Fabianski, Angel Rangel (capt), Kyle Bartley, Jordi Amat, Dwight Tiendalli, Tom Carroll (Federico Fernandez, 8), Jonjo Shelvey, Gylfi Sigurdsson, Nathan Dyer, Modou Barrow (Jefferson Montero, 61), Bafe Gomis (Nelson Oliveira, 76).
Gerhard Tremmel, Kyle Naughton, Jay Fulton, Marvin Emnes.
5,928 (580 away)
The game got off to a poor start for the Swans, with the visitors reduced to ten men after just six minutes.
Defender Matt Kilgallon struck a long ball over the top of the Swans defence for Josh King to chase, and when he went down following contact with Kyle Bartley, referee Craig Pawson showed the centre-back the red card.
From the free-kick some 20 yards out, Lukasz Fabianski parried Tom Cairney's effort before King poked the loose ball wide from eight yards.
Swans boss Garry Monk immediately made a change as Federico Fernandez replaced Tom Caroll to restore a four-man defence.
King looked lively for Blackburn, and his trickery inside the visitors' box teed up Cairney, but Fabianski collected the danger.
But the Swans took the lead after 20 minutes with a stunning strike from Gylfi Sigurdsson. He cut inside from the left before firing a thunderbolt into the top corner from 25 yards.
The celebrations in the away end had barely settled down before the hosts were back on level terms two minutes later.
Markus Olsson's cross was nodded down by Cairney at the back post, and Chris Taylor controlled before shooting on the turn past Fabianski from eight yards.
The Swans looked to regain their lead soon after as a surging run by Sigurdsson led to Dyer seeing two efforts blocked inside the box.
Blackburn were then forced into a change as David Dunn replaced the injured Lee Williamson.
And, just before the break, Bafe Gomis failed to fully connect with Dwight Tiendalli's cross after he had latched onto Jordi Amat's fine through ball.
HALF-TIME: Blackburn 1 Swans 1
Both teams managed to carve open opportunities in the opening exchanges of the second half.
Gomis saw his powerful effort blocked by Shane Duffy and then King's trickery saw him beat Fernandez before Fabianski snuffed out his cross.
Cairney spurned a decent chance when Dunn found him inside the box, with the midfielder firing well off target.
Both sides made a change at the hour mark as Blackburn introduced Rudy Gestede in place of the lively King while, for the Swans, Jefferson Montero came on for Modou Barrow.
And after further substitutions it was Gestede who edged Blackburn ahead when he poked home from close range after he took advantage of a quickly-taken corner in the 78th minute.
The Swans needed a quick response and they almost got it as Sigurdsson's pass into the box for Angel Rangel split the Blackburn defence open, but Duffy's perfectly-timed challenge denied the Spaniard.
Sub Nelson Oliveira, on for Gomis, then drove straight at keeper Simon Eastwood after Montero's pass had been flicked into his path by Sigurdsson.
But Blackburn booked their place in the fifth round after Craig Conway's dipping effort squirmed under Fabianski and rolled over the line in the 89th minute.
And things got even worse in added-on time as Sigurdsson was dismissed for a challenge on Taylor.