Barnsley Capital One cup hopes are over for another year as Southampton’s Premier League class shone through.
The Reds were second best by some distance on a night when manager Dave Flitcroft finally lost faith in struggling keeper Luke Steele.
The shock pre-match team news came with veteran stopper Mike Pollitt getting the nod ahead of Steele following his short-term loan capture from Wigan in the hours leading up to the game.
Out-of-form Steele was on the bench after shipping 12 goals in four Championship games, while Jim McNulty - making his first start this term - stepped up to replace suspended centre-back Jean-Yves M’Voto and Marcus Pedersen was in instead of Chris Dagnall up front.
The Premier Leaguers ran the show in the first half and deservedly led at the interval. They might have rested a number of regular first-team stars - including new England hero Rickie Lambert - but the Saints highlighted just how vast the gulf in quality is between the two divisions.
The visitors ought to have gone in front inside two minutes, only for Gaston Ramirez to somehow fire wide after charging in front of a static Reds back line.
The Saints went in front after 26 minutes. Teenage debutant Lloyd Isgrove won a block tackle with Tom Kennedy, and as the ball flew loose inside the box, Steven Davis drilled past 41-year-old Pollitt.
The Reds did have their moments, however, with Norwegian striker Pedersen making the most of his first start as he twice fizzed low drives narrowly wide.
The silky Saints all but secured victory three minutes after the restart. The ball fell kindly to Jay Rodriguez on the edge of the box as Davis’s shot was blocked, but the former Reds loan striker - now an established top flight hit-man - curled an exquisite strike past Pollitt.
Within two minutes it was almost 3-0 as Rodriguez struck a shot against the post, but credit to the Reds, they grabbed a goal back in the 52nd minute when Stephen Dawson lashed home his first of the season.Jacob Mellis went close as the hosts briefly threatened, but in the 66th minute it was 3-1 as Emmanuel Mayuka left Scott Golbourne on the seat of his pants slotting past Pollitt.
Southampton wrapped up their clinical victory with two further goals in the dying minutes. Davis added his second goal of the night from the penalty spot.
McNulty clearly tripped the on-rushing Mayuka, and though Pollitt got a hand to Davis’s effort from 12 yards, the ball nestled in the corner of the net.
In stoppage-time Ramirez atoned for his early howler.
Barnsley (3-5-2): Pollitt 7; Wiseman 7, McNulty 6, Kennedy 5 (Scotland 54, 6); O’Brien 6, Mellis 7, Dawson 7, Etuhu 6 (Cywka 65, 6), Golbourne 5; O’Grady 6, Pedersen 7 (Dagnall 54, 6).
Subs not used: Steele, McCourt, Noble-Lazarus, Jennings.
Southampton (4-3-1-2): K Davis 7; Clyne 7, Yoshida 7, Fonte 7, Fox 8; Cork 8, S Davis 8, Isgrove 6 (Rowe 71, 7); Ramirez 8; Rodriguez 8 (Reed 79, 6), Mayuka 7 (Sinclair 89, 6).
Subs not used: Ward-Prowse, Chambers, Gazzaniga, Stephens.
Referee: Scott Duncan. Attendance: 6,574