Jersey claimed one of the greatest results in their history, beating Championship leaders Worcester 23-21 to end the Warriors' 24-game winning run.
A late long-range drop-goal from Aaron Penberthy proved to be the difference between the sides.
Fautua Otto's try had earlier put Jersey ahead but the visitors hit straight back with Sam Smith's score.
Sam Betty's try extended the Worcester lead but Ryan Hodson's try kept Jersey in touch before Penberthy's winner.
|Worcester already booked in for the play-offs|
|Worcester and Bristol sealed their place in the four-team Championship play-offs a month ago - with still seven fixtures of the campaign remaining.|
Heading into the game, Worcester held a one point lead over Bristol at the top of the Championship table and had not lost since an opening day defeat to their main title rivals.
Jersey dominated the early possession and territory but Warriors led 3-0 before Samoan winger Otto chased onto his own kick and caught a kind bounce for a superb solo try.
But straight from the restart Worcester were back ahead as Otto hesitated and let the ball bounce, this time awkwardly, and Smith capitalised in the corner.
Andy Symons and Penberthy exchanged penalties and the visitors led 14-10 at the break.
Worcester's second try came from a quick move from right to left, with full-back Chris Pennell almost crossing in the corner before a drive from close range saw Betty crash over.
But the hosts were back to within a point as they kicked for the corner, instead of a relatively straight-forward shot at the posts, and were rewarded as flanker Hodson grounded the ball from the resulting line-out drive.
Jersey's biggest home crowd of the season sensed something special, and with five minutes on the clock Penberthy's drop-goal attempt had just enough on it to go over and put his side in front.
Earlier in the campaign Worcester had needed and history could have repeated itself when Symons lined up a late kick but he pulled his effort well wide.
At the other end Penberthy missed with a penalty of his own but it was not to prove costly and Jersey could celebrate a thrilling victory.
The Channel Islands outfit remain in eighth spot in the Championship, while Worcester drop to second, three points behind new leaders Bristol.
Jersey: Penberthy; Foster, Locke, Bishop, Otto; Robling, Fisilau; Lancuba, Buckle, Herriott, Phillips, Markham, Rae (capt), Hodson, Haining.
Replacements: Lockwood, Garcia-Veiga, Williams, Noone, Kaho, Glynn, Bentley.
Worcester: Pennell; Smith, Stelling, Symons, Biggs; Mills, Mulchrone; Bower, Annett, Schonert, Williams, Thomas, Betty, Lewis, van Velze (capt).
Replacements: George, Rapava Ruskin, Rees, O'Shea, Arr, Fatiaki, Howard.