Match ends, Swansea City 5, Nottingham Forest 1.
Swansea City set up an FA Cup fifth-round meeting with Manchester City thanks to a 5-1 thrashing of Nottingham Forest.
Liam Cullen and Matt Grimes claimed two goals apiece and Ollie Cooper's fifth ensured Swansea reached the last 16 for the third time in four seasons.
They will host Pep Guardiola's City, who won at Cheltenham, in February.
Swansea's progress was rarely in doubt as they won the battle of two much-changed sides with ease.
Boss Steve Cooper was contemplating hosting Cheltenham for a while later in the day as they led Manchester City 1-0.
But the visitors scored three times in the last 10 minutes to ensure their trip to Liberty Stadium with the tie to be played between Tuesday, 9 and Thursday 11 February.
Swansea had already beaten Forest in the Championship this season, where the Welsh club are chasing promotion while Chris Hughton's men are attempting to pull clear of a relegation scrap.
Hughton made 10 changes compared with Cooper's seven on Saturday, and it was Forest's second string who were quickly on the back foot as Wayne Routledge broke the offside trap and centred for academy product Cullen to volley home only his second Swansea goal.
Jamal Lowe - an early replacement for the injured Routledge - saw a heavy touch cost him the chance to double the lead, before Swansea skipper Grimes found the target from 25 yards, his spectacular drive flashing into the net with Jordan Smith motionless in the Forest goal.
The visitors briefly improved after the break, hauling themselves back into the contest when Joe Lolley's persistence down the left allowed Anthony Knockaert to drill home from close range.
But Forest's hopes of a comeback did not last long, as Ryan Manning tumbled under Joe Worrall's challenge and Swansea were awarded a contentious penalty.
Grimes stepped up to send Smith the wrong way from the spot, before Cullen scored the goal of the day after good work from Yan Dhanda and Manning.
Swansea finished with 10 men after Cullen limped off with an ankle injury, but that did not stop substitute Cooper marking only his second senior appearance with his first goal at this level, a left-footed shot which went through Smith's legs and squirmed over the line.
Swansea head coach Cooper:
"Loads and loads of pluses.
"I didn't love the start of the second half. Although I am not going to dwell on that, it is a reminder that we need to start games and halves better.
"But we shouldn't talk about that for too long. There were too many things in the game to make us pleased.
"Culls [Liam Cullen] has deserved the goals. I said to him not so long ago that we have just been waiting for those chances to drop to him, because he will score those chances."
Nottingham Forest manager Hughton:
"Even though Swansea made a fair few changes, what they are is a team in a confident mood.
"We made too many errors, which you can't afford to do against a form team. We accept that in the first half we were second best.
"The pivotal part of the game, in what was our best period having got back to 2-1, was the penalty. The ref, for me, makes a dreadful decision. I was quite confident from where I was that it wasn't a penalty.
"The lad's gone down. I don't like to use the word diving, but from the angles I've seen there's no contact. The lad drags his leg a little bit and it's certainly simulation."
- 5GuehiSubstituted forBidwellat 66'minutes
- 23RobertsSubstituted forGarrickat 76'minutes
- 14HourihaneSubstituted forCooperat 66'minutes
- 8GrimesSubstituted forFultonat 65'minutes
- 21DhandaBooked at 90mins
- 15RoutledgeSubstituted forLoweat 20'minutes
- 20CullenSubstituted forat 79'minutes
- 10A Ayew
- 16JenkinsonBooked at 10mins
- 4WorrallBooked at 69mins
- 13BongSubstituted forBlackettat 76'minutes
- 6Mbe Soh
- 14BachirouSubstituted forRibeiro Diasat 45'minutes
- 28KnockaertSubstituted forMightenat 76'minutes
- 15FreemanSubstituted forGuerreroat 45'minutes
- 18Ribeiro Dias
- Kevin Friend
- Shots on Target
Second Half ends, Swansea City 5, Nottingham Forest 1.
Foul by Carl Jenkinson (Nottingham Forest).
Oliver Cooper (Swansea City) wins a free kick in the defensive half.
Corner, Nottingham Forest. Conceded by Oliver Cooper.
Joe Lolley (Nottingham Forest) wins a free kick in the attacking half.
Foul by Oliver Cooper (Swansea City).
Tyler Blackett (Nottingham Forest) wins a free kick in the defensive half.
Foul by Jamal Lowe (Swansea City).
Yan Dhanda (Swansea City) is shown the yellow card.
Foul by Tyler Blackett (Nottingham Forest).
Jordan Garrick (Swansea City) wins a free kick on the right wing.
Goal! Swansea City 5, Nottingham Forest 1. Oliver Cooper (Swansea City) left footed shot from the left side of the box to the centre of the goal.
Attempt blocked. Jamal Lowe (Swansea City) right footed shot from outside the box is blocked.
Attempt missed. Miguel Ángel Guerrero (Nottingham Forest) header from the centre of the box is close, but misses to the right. Assisted by Carl Jenkinson with a cross.
Foul by Oliver Cooper (Swansea City).
Miguel Ángel Guerrero (Nottingham Forest) wins a free kick in the defensive half.
Liam Cullen went off injured after Swansea City had used all subs.
Corner, Swansea City. Conceded by Jordan Smith.
Attempt saved. Oliver Cooper (Swansea City) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Jordan Garrick.
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