Jersey lifted the Siam Cup for the eighth consecutive year despite new restrictions on player-selection.
Guernsey were 14-3 ahead after tries from Cameron Craine and Ned Brown, but Nick Selway's score helped narrow the gap to a single point at half-time.
Sam Whitehead went over early in the second period before two Stephen de Ste Croix scores put the reds in front.
Centre Donovan Sanders scored in the corner late on to seal a 33-19 win for the visitors.
For the first time this year, Jersey's professional players had to have been in the island for three years to be eligible for the Siam, leading coach Harvey Biljon to declare his side the underdogs in the build up to the game at Footes Lane in Guernsey.
|Jersey's Siam Cup dominance|
|2016 - Guernsey 19-33 Jersey|
|2015 - Jersey 48-3 Guernsey|
|2014 - Guernsey 7-38 Jersey|
|2013 - Jersey 41-8 Guernsey|
|2012 - Guernsey 0-29 Jersey|
|2011 - Jersey 73-5 Guernsey|
|2010 - Guernsey 0-36 Jersey|
|2009 - Jersey 34-6 Guernsey|
The visitors started brightly though and Aaron Penberthy, on his final outing for the club, landed one of three early penalties to put Jersey ahead.
Guernsey seemed to grow in confidence as the half wore on, and prop Craine powered over from a line-out as the Raiders were rewarded for kicking for the corner rather than the posts.
Centre Brown, later to be named the BBC's Man of the Match, burst through for his side's second and the Greens found themselves 14-3 ahead and with real hopes of lifting the Siam Cup for the first time since 2008.
But hooker Selway went over from a maul five minutes before half-time to keep the visitors in touch, before Penberthy's penalty reduced the arrears to 14-13 at the break.
Jersey wing Ryan Morgan was sent to the sin bin soon after the restart for a mistimed tackle, and Guernsey made the man advantage count when Whitehead was found out wide as the spare man and touched down.
The home side were soon to be down to 14 men themselves when replacement Jason Batiste, who had come on for injured Owen Thomas, was shown yellow and the Reds capitalised with flanker de Ste Croix crashing over from a maul before Penberthy's penalty put them ahead.
The amateur Sarnians, who play in National Three London, began to tire as Jersey's pack started to dominate. De Ste Croix, who captains the amateur Jersey Athletic, went over for his second from another maul before Sanders scored in the corner to extend the winning run.
Earlier in the day Jersey had also won the second-team fixture between the islands, 47-12, but Guernsey took the veterans match 33-10 and retained the women's Siam Cup with a 41-12 victory.
Guernsey: Sayer; Whitehead, Brown, Campbell, Barnes; Thomas, Nixon; Craine, Ceillam, Batiste, Hillier, Merrien, Martin, Rice, Thomas.
Replacements: Ashplant, Malagodi, Gardner, Sharrott, Batiste, Challinor, Armstrong.
Jersey: Burroughs; Morgan, Sanders, Falle, Dawson; Penberthy, Dudley; McCarthy (capt), Selway, Pople, Campbell, Howgate, Rae, Corson, Rennison.
Replacements: Felton, Carter, De Ste Croix, Clyde-Smith, Jeffrey, Glendening, Stevens.