Former Jersey prop Marc Thomas scored two tries on his return to end the Reds’ two-match win run.
Louis Brown also crossed for Carnegie in the first half to keep the Yorkshire travellers in contention at 7-5 and poised to reverse their recent ailing fortunes.
A penalty kick – the last play of the game in fact – from Carnegie’s Pete Lucock put the final nail in Jersey’s coffin by chalking off the losing bonus point.
Jersey opened the scoring when the backs benefited from good lineout ball. Tom Pincus came into the line at pace then sent fellow winger Josh Hodson over in the corner.
Apakuki Ma’afu was sin-binned for a late tackle and, in his absence, Carnegie got on the scoreboard, Lucock floating a cross-field kick for Brown to score wide out, too far though for the extras to be added.
But that didn’t look to matter from the restart as Yorkshire Carnegie collected and scrum-half Will Homer and Brown combined to get within striking distance. However, the winger was bundled into touch mere millimetres short of the Jersey try line. Carnegie enjoyed plenty of field position for the remainder of the first half, but simply couldn’t turn possession into points.
Brendan Cope extended Jersey’s slender advantage to five points early in the second half with a penalty conversion.
But Carnegie recaptured control of the game and penned the Reds into their territory. The Yorkshire side didn’t have everything its own way, however, as Jersey made a nuisance of themselves especially at the lineout.
That said, Carnegie enjoyed enough ball to threaten from mauls and twice Thomas burrowed over from close range to claim his first tries for his new club and condemn his old one to defeat.
Jersey Reds: Slowik, Pincus, Ma’afu, Abrahams (Bryant 68), Hodson, Cope, Hardy (Dudley 77), Woolmore (Brodley 73), Selway (Saunders 60), Armstrong (Atalifo 58), Sexton, Voss, Rogerson, Joyce, Nagle-Taylor (Pitman 48, Kolo’ofa 64), Rogerson.
Yorkshire Carnegie: McColl (Forsyth 27), Watkins, Burdon, Casson, Brown, Lucock, Homer (Fox 73), Thomas, Buckle, Beech, Whetton (West 66), Myerscough, Beck, Mayhew, Stedman (Bainbridge 73). Unused subs: Newborn, Capps, Thraves.
Referee: Fergus Kirby.