Southampton have sealed their place in round four of the League Cup by thrashing MK Dons 6-0 in the third-round tie at Stadium MK.

Ronald Koeman's side made five changes for the game and one of those paid dividends after just five minutes when Jay Rodriguez, brought into the attack, curled the first shot of the game past David Martin off the post to open the scoring.

Cedric Soares curled over from Shane Long's pull-back as Saints continued to threaten in the early stages and they doubled their lead with just 10 minutes on the clock when Sadio Mane beat a defender and coolly chipped Martin after going one on one with the goalkeeper.

Maarten Stekelenburg had to keep out a fierce Carl Baker drive as the Dons looked to recover from their poor start, but the visitors extended their advantage further on 25 minutes when Long beat the offside trap to square for Mane to slot home.

Martin prevented Juanmi from making things worse for the Championship side minutes later with a good reaction save and Rodriguez fired wide as Southampton continued to threaten before the break, and it was four soon after the restart.

Rodriguez converted from the penalty spot after Long was tripped in the box, and the Dons' luck got even worse when Kyle McFadzean's clearance hit Long and bounced into the net for a fifth.

The visitors still were not finished, however, as Long added his second of the night to make it a fifth consecutive defeat for the Dons and ensure that Southampton emphatically progressed to round four.