The Reds saved a get-out-of-jail card until the final minute of the match, celebrating wildly as TJ Harris steered a 12-man maul to the Hartpury line and touched down for the winning score.
There was relief for the visitors in claiming the points from a match they could have won in the first half, but missed opportunities meant a far tighter conclusion that was harsh on the home side after a plucky effort.
The game was another weather-affected affair, with wind blowing down the Alpas Arena accompanied for the most part by a steady drizzle.
The conditions were in the Reds’ favour and enabled them to dominate territory and possession in the first half. Several opportunities involved penalties kicked to touch inside the Hartpury 22, but winning lineout ball proved elusive on occasions.
A series of attacking phases eventually culminated in a try in the corner from Janco Venter as the ball was worked quickly out from Will Homer and Brendan Cope.
Otherwise the Reds were unable to get points on the board, and their frustration was magnified in the closing stages of the half when Hartpury finally managed to get out of their half.
Pressure on the Red defence eventually led to a penalty in front of the posts and a yellow card to Charlie Beckett for killing the ball. Josh Bragman slotted the kick, and was again on target soon after the break after Leroy Van Dam was pinged for failing to release the ball after running back a kick.
Hartpury used the conditions to control the game during most of the second half. The home side rarely looked like scoring, but their one-point lead meant the onus was on the opponents to try and claim the next score.
In fact it was another Bragman three-pointer that stretched the lead with five minutes to play, and to make matters worse the Reds were down to 14 men after Venter saw yellow for a clumsy no-arms challenge.
But a collective determination in Jersey ranks was evident in the dying moments, retaining possession during a series of lineouts, mauls and penalties that eventually saw replacement Tom Jubb sin-binned for bringing down a maul.
At the next lineout Hartpury appealed for a knock-on as Jake Upfield momentarily lost the ball after catching it at the lineout, but another penalty was the verdict as ex-Jersey back row player Seb Nagle-Taylor was ruled to have entered the breakdown from the wrong side.
After a losing conclusion to 2019 when crucial lineout ball was lost in the dying moments of the home game with London Scottish, Harris held his nerve to help his side win four consecutive lineouts, including the last one which set up the winning score.
After wins for Ealing Trailfinders and Cornish Pirates, while Newcastle remained unbeaten but Coventry suffered last-kick defeat at Ampthill, the Reds finished round 8 on 25 points, level with Ealing, and four behind second-placed Cornish Pirates, who travel to Stade Santander International next Saturday.
Hartpury University (1-15)
Dan Murphy, Will Crane, Alex Gibson, Tom Everard, Will Safe, Iain Grieve, Jack Preece, Seb Nagle-Taylor; Luke Carter (capt), Josh Bragman; Sam Goatley, Joe Margetts, Robbie Smith, George Simpson; Mike Wilcox.
Replacements: Akapusi Qera (for Grieve 49 mins), Tiff Eden (Eves 53), Des Merrey (Murphy 57), Will Tanner (Crane 70), Mike Flook (Gibson 70), Tom Jubb (Everard 70, YC 76), Harry Wilson (Goatley 77). Not used: Harry Cochrane.
Jersey Reds (1-15)
Roy Godfrey, Nic Dolly, Leeroy Atalifo, Charlie Beckett (YC 40), Rory Bartle, Max Argyle, Josh Bainbridge (capt), Janco Venter (YC 70); Will Homer, Brendan Cope; Leroy Van Dam, Rodney Iona, James Newey, Alex Morgan; Greg Dyer.
Replacements: TJ Harris (for Dolly 51 mins), Alec Clarey (Atalifo 51), George Spencer (Newey 53), Kyle Hatherell (Argyle 64) Luc Jones (Morgan 64), Harry Morley (Godfrey 67), Jake Upfield (Beckett 73). Not used: Jack Stapley.
REFEREE: George Selwood. Assistants: Jamie Leahy, Gregg Dawson
Half Time: 3-5
Penalties: Bragman 40, 42, 72
Tries: Venter 18, Harris 79