The Hatters progressed in the cup thanks to a dramatic 2-1 win over Everton on Saturday, while Roberto De Zerbi's men rediscovered their clinical touch in a 5-2 crushing of Sheffield United.
Match preview
Almost four months to the day since earning their first-ever Premier League win with a 2-1 victory over Everton at Goodison Park, recent history repeated itself for both clubs in Saturday's Merseyside meeting, allowing Rob Edwards's men to dream of a Wembley sojourn for a little while longer.
After the unfortunate Vitaliy Mykolenko turned into his own net to open the scoring, Luton's stand-in goalkeeper Tim Krul allowed Jack Harrison's strike to squirm under his body for the hosts' equaliser, but Cauley Woodrow was the Dutchman's saviour with the pivotal strike six minutes into second-half injury time.
As well as representing a second successive 2-1 win over Everton at their Goodison Park base, Saturday's memorable triumph also saw Luton make it back-to-back away victories by that scoreline in all tournaments, having also seen off Bolton Wanderers in January 16's FA Cup clash after coming away from Burnley's headquarters with a 1-1 draw.
With temperatures dropping over the winter period, Luton have stoked the fire to go four games unbeaten across all competitions, while losing just one of their last seven matches since December 23, and the Hatters only have a one-point disadvantage to make up to 17th-placed Everton having played a game fewer.
The Toffees' failure to beat Fulham this week would therefore open the door for Edwards's men to escape the demotion trapdoor, and while three of their last four Premier League home games have ended in defeat, there was little shame in suffering narrow losses to Arsenal, Manchester City and Chelsea.
Since their Premier League inauguration, Luton have not been beaten by more than one goal in a top-flight fixture at Kenilworth Road and have only failed to make the net bulge against Tottenham Hotspur, but Brighton warmed up for their taxing Hatters test in perfect fashion at Sheffield United's Bramall Lane.
Newly-signed Blades goalkeeper Ivo Grbic experienced a true baptism of fire in between the sticks, being beaten three times by Joao Pedro - twice from the penalty spot - while Facundo Buonanotte and Danny Welbeck also found the mark either side of Pedro's heroic hat-trick.
There were shades of Brighton's third-round affair with Stoke City - which ended 4-2 to the Seagulls - in their pummelling of Sheffield United, but offensive consistency is still eluding De Zerbi's side, who have drawn blanks against West Ham United and Wolverhampton Wanderers in their opening Premier League fixtures of 2024.
In spite of the fact that only three of Brighton's last 15 top-flight games have seen the Seagulls prevail, De Zerbi's side remain in the mix for back-to-back continental qualifications, occupying seventh place in the Premier League table with just a three-point gap separating them from West Ham in sixth.
Drawing 0-0 with West Ham on January 2 at least saw Brighton register their first away clean sheet of the Premier League season, and the Seagulls made light work of Luton in the first weekend of the new term, subjecting them to a harsh welcome to life in the big time with a 4-1 Amex annihilation.
Luton Town Premier League form:
L
L
W
W
L
D
Luton Town form (all competitions):
W
L
D
D
W
W
Brighton & Hove Albion Premier League form:
D
L
D
W
D
D
Brighton & Hove Albion form (all competitions):
D
W
D
W
D
W
Team News
As well as a place in the fifth round, Luton travelled home from Goodison Park without any additional fitness concerns, but captain Tom Lockyer and Marvelous Nakamba - a long-term knee victim - will not be seen on the pitch again anytime soon, while Gabriel Osho was also absent from the squad to face Everton for unexplained reasons.
Mads Andersen's calf problem may not heal in time for the defender to be involved this weekend either, while Issa Kabore's Burkina Faso made it through to the Africa Cup of Nations knockout rounds, rendering the right-back unavailable for domestic duty for a little while longer.
However, midfielder Jordan Clark is back in the fold following an FA Cup suspension to boost Edwards's bench options, but Woodrow's remarkable late winner at Goodison Park is unlikely to be enough for a place in the Premier League XI.
Meanwhile, Brighton's thrashing of Sheffield United saw centre-back Igor make a welcome return from an Achilles issue, but Solly March, Joel Veltman and Julio Enciso will not play any part in Tuesday's game owing to their knee injuries.
Ansu Fati's thigh concern is still giving him grief too, although the Barcelona loanee should be the first name out of the treatment room next month, while Kaoru Mitoma and Simon Adingra are still competing at the Asian Cup and AFCON respectively.
While Woodrow's injury-time strike in the FA Cup may not be rewarded with a start, Welbeck is a viable alternative to Evan Ferguson in the final third, and Bart Verbruggen should also hand the gloves back over to Jason Steele.
Luton Town possible starting lineup:
Kaminski; Mengi, Osho, Bell; Ogbene, Barkley, Lokonga, Doughty; Townsend, Adebayo, Morris
Brighton & Hove Albion possible starting lineup:
Steele; Webster, Dunk, Igor; Hinshelwood, Gross, Gilmour, Estupinan; Buonanotte, Welbeck, Pedro
We say: Luton Town 1-2 Brighton & Hove Albion
Always a threat from crosses and set-pieces, a Luton side who are seldom shut out at Kenilworth Road can power their way through a volatile Brighton side, who have lacked steadiness in both boxes during the winter period.