Ryan Lamb kicked a last-minute penalty to send Worcester top of the table and leave Jersey broken-hearted at Sixways.
Drew Locke's late interception try looked to have given the islanders a draw, after they had trailed 22-5.
But Lamb recovered from an earlier miss to slot home.
Flanker Mat Gilbert's two tries, allied to one from Val Rapava Ruskin and a penalty try, earned Worcester the bonus-point win which lifts them clear of season-long leaders Bristol.
It was Worcester's 10th consecutive win in all competitions, but despite the result, they were given a rude awakening by Jersey, who produced one of their best performances of the season as flanker Mick Noone also crossed twice, supplemented by a penalty try of their own.
Referee John Meredith also saw fit to hand out yellow cards to home lock Mike Williams, as well as Jersey replacement Sam Lockwood.
Worcester full-back Chris Pennell made a second-half appearance, his first game since the first day of the season following the injury that sidelined him from England's autumn internationals.
|Analysis - Tim Pryor, BBC Radio Jersey|
|"Although it sounds strange to say, this defeat was probably one of Jersey's greatest results. A narrow loss against a former Premiership club, in their own back yard. There will have been mixed emotions on the flight back to the Channel Islands, with some delighted to have come so close to an upset and others gutted that they could not quite pull it off."|
The hosts had opened up a healthy lead heading towards half-time, with Gilbert and Georgian prop Rapava Ruskin going over from driving mauls.
But former Leicester Tigers back-row Noone got the islanders on the board after a spell of pressure before the break to give Jersey supporters renewed hope.
Gilbert's second try, early in the second period, re-established a 17-point cushion for the Warriors, but the visitors hit back just a few minutes later as Noone grabbed his second of the night.
Jonny Bentley's penalty reduced the gap further and then Jersey pulled level when Meredith awarded a penalty try following a passage of play which saw Williams sent to the the sin-bin.
The man advantage did not last long as Jersey's front-row replacement Lockwood was shown yellow and Worcester moved back into the lead through a penalty try of their own, securing a bonus-point at the same time.
Jersey, though, fancied more than a losing bonus-point themselves and winger Locke set up the thrilling finale as he intercepted in his own half and had the legs to make the try line.
Bentley converted and the scores were tied at 29-29 with time ticking away, but after missing one late penalty opportunity, fly-half Lamb was gifted another with seconds remaining and this time made no mistake as he slotted the ball between the posts.
Worcester: Howard; Smith, Stelling, Mills, Biggs; Lamb, Mulchrone; Rapava Ruskin, Annett, Daniels; Williams, O'Shea; Cox, Gilbert, van Velze (capt)
Replacements: Sowrey, Bower, O'Donnell, Thomas, Bruzulier, Symons, Pennell
Jersey: Jones-Davies; Locke, Bishop, Robling, McCrea; Bentley, Glynn; Lancuba, Harris, Selway; Campbell, Rae (capt); Kaho, Buckle, Noone
Replacements: Lockwood, Garcia-Veiga, Herriott, Haining, Hodson, Dudley, Pointer
Referee: John Meredith