|Lambert (pen) 15|
Papa Waigo 50
|Ref: Mr S Mathieson
|| Attendance: 73,476|
Striker Rickie Lambert hit his 31st goal of the season to set the Saints marching on to a comprehensive Johnstone's Paint Trophy Final victory.
Alan Pardew's team were in control from the moment Lambert's 15th minute penalty struck the Carlisle net.
And further goals by midfielder Adam Lallana, striker Ndiaye Papa Waigo and winger Michail Antonio meant that the League 1 team equalled the Final's biggest winning margin in the 27-year history of The Football League competition.
Substitute Gary Nadine scored a late consolation goal, but on an afternoon of bright Wembley sun shine the Cumbrians were overshadowed by the Saints and 44,000 south coast fans - over half of the excellent crowd - were left to celebrate victory in what has been their team's first ever season of Trophy football after being relegated last May.
Lambert's penalty, awarded for a hand-ball by central defender Peter Murphy, was clinically despatched just inside goalkeeper Adam Collin's left hand post.
Carlisle had made a positive start but Saints, buoyed by taking the lead, took the initiative and twice within a minute Lallana forced Collin into goal line saves from cleanly-hit shots.
Collin then had to make a smart 35th minute stop from Antonio, the keeper moving quickly to his left to turn aside the right winger's angled 15 yard drive.
Two minutes later the Cumbrians went close to equalising when left winger Matthew Robson crossed for central defender Ian Harte to land a header on top of the crossbar
But a minute before the interval Saints doubled their lead, Lallana heading in at the far post after Lambert had helped on Antonio's long throw.
And four minutes after break striker Ndiaye Papa Waigo hit the killer goal with a header into the empty net after Collin had brilliantly blocked Antonio's close range shot from Lambert's low cross.
Antonio completed the scoring on the hour with the best goal of he game, a superbly struck 18 yard drive after neatly chesting down an awkwardly bouncing down to give himself space.
The Cumbrians battled manfully in the final half-hour to gain a foothold in the game and got their consolation six minutes from time. Central defender Ian Harte whipped in a free-kick from the left and Nadine rose to glance a header inside the far post.
Carlisle United (4-4-1-1): Collin; Keogh, Murphy, Harte, Horwood; Bridge-Wilkinson (Anyinsah 61), Clayton, Thirwell (Taiwo 79), Robson; Kavanagh (Madine 74); Dobie.
Substitutes not used: Pidgeley, Kane.
Southampton (4-4-2): Davis; Harding, Fonte, Jaidi (Perry 90), Mills; Antonio, Hammond, Wotton (Connolly 85), Lallana; Lambert, Papa Waigo (Gillett 76).
Substitutes not used: Bialkowski, James