United required a 100th minute penalty to claim an undeserved 3-2 win at this ground in the Premier League on Saturday but found things a lot easier in this latest encounter.
Pogba found the net via a deflected free-kick 10 minutes from time after being brought off the bench with United toiling at the time, albeit a goal to the good through Scott McTominay's first-half header.
Juan Mata set up that opener and was also on target with the visitors' second goal of the game before Pogba took over, sealing a third win in a row for Ole Gunnar Solskjaer's men in all competitions.
1 - Paul Pogba has scored his 33rd goal in all competitions for Manchester United, but tonight is his first from a direct free-kick. Laser. pic.twitter.com/jyoOr2GDNo— OptaJoe (@OptaJoe) September 30, 2020
Bruno Fernandes, the scorer of United's dramatic goal at the same venue four days ago, was left out of the squad as Solskjaer made 10 changes, compared to nine for Brighton.
Those mass changes perhaps explain the disjointed nature of the first half, with McTominay finding a way through a minute before the interval from the only real opportunity.
Mata sent in a teasing free-kick from the right and McTominay was left all alone five yards out to head past Jason Steele - his first goal since the Manchester derby in March.
United were grateful to the reactions of back-up goalkeeper Dean Henderson for keeping them level with 67 minutes played, getting down to his left to tip Leandro Trossard's effort wide of the post.
The visitors used that warning wisely by scoring an all-important second goal six minutes later through Mata, who controlled Donny van de Beek's delightful backheeled pass and picked out the bottom-right corner.
Pogba, introduced along with Marcus Rashford, made certain of a place in the quarter-finals with a free-kick from 20 yards that took a telling deflection off the wall on its way past Steele.
What does it mean? - Silverware beckons for Solskjaer?
United legend Roy Keane suggested this week that Solskjaer will likely have to get his hands on some silverware this season if he is to avoid being sacked.The EFL Cup surely offers Solskjaer his best hope of achieving that aim, with his side now just two steps away from the Wembley final.
Unlike last weekend, United had more of the ball than their opponents (56 per cent), scored from half of their six attempts on target and - perhaps best of all for Solskjaer - they kept the opposition out.
Mata quality shines through
In a low quality game devoid of any major talking points - in complete contrast to Saturday's thriller - Mata's class told with his assist for McTominay's opener and his own second-half strike.
The Spaniard has now been directly involved in 13 goals in his last 15 starts for United, including a strike in the last round against Luton Town.
Ighalo and James unable to get into game
A lot has made been made about United's lack of squad depth and that has become even more apparent in their wins over Luton and now Brighton in this competition.
No United starters managed fewer touches of the ball than Ighalo (21) and James (24), explaining why Solskjaer turned to Pogba and Rashford with 20 minutes to go.