The Swans lined up with first teamers including Kristoffer Peterson, Barrie McKay and Declan John at Landore, while Boro included five who have been in senior squads this season; Sol Brynn, Connor Malley, Hayden Hackney, Stephen Walker and Tyrone O’Neill.

Swansea took the lead with 20 minutes played, when Liam Cullen showed sharp footwork in Boro’s area to evade his marker, squaring cross the six yard box for Peterson to fire into an unguarded net.

Boro went close to an equaliser a few minutes later when Malley rifled against the post from the edge of the area after being teed up by Tyrone O’Neill.

Malley then turned provider, his pull-back finding Stephen Wearne unmarked but the Boro midfielder striking his shot straight at Josh Gould in the Swans goal.

Swansea’s lead was doubled when Cullen slammed home in some style, beating Sol Brynn from a tight angle on the edge of the 18-yard box.

A Boro pursued a way back into the contest, Daniel Dodds flashed a shot across goal that was just out of reach of O'Neill with the goal at his mercy.

At the other end, Peterson and Cullen each went close to adding to the tally and drew two good saves out of Brynn, before McKay shot low and just wide.

Swansea did make it three at the end of another swift counter-attack, Cullen curling in his tenth goal of the season, another impressivee strike from the edge of the area.

Into the second half, and again it was Connor Malley who looked most likely for Boro, a delightful run which included nutmegging a City defender thwarted at the last by keeper Gould.

Boro did pull one back when a Swans man was adjudged to have handled inside the area, Ste Walker stepping up and sending Gould the wrong way from the spot.

But Swansea were swift in their response, Peterson sending one a whisker wide before tucking into the corner first-time from inside the area to make it 4-1.

And the home side added a final flourish, Cullen earning his hat-trick when he headed home a rebound from Peterson with minutes to play.

Swansea: Gould, Rushesha, Evans, Cooper, John, Evans, De Boer, Cooper, McKay, Peterson, Cullen. Unused subs: Webb, Thomas, Bevan, Evans, Jones-Thomas

Boro: Brynn, Dodds, Reading, Dale, Hood, Hackney, Malley (Folarin), Wearne, Jones (Robinson), Walker, O’Neill (Burrell). Unused subs: Flatters, Green