The Islanders became only the second team to win at Castle Park this season when scoring a last-minute converted try by centre Fautua Otto to claim the spoils.
In scoring three of the four tries the Reds will feel they deserved the win but Knights will be reflecting on several first half chances they failed to convert. There will also be questions about some untypical defence in the build-up to a couple of Jersey’s tries.
The closeness of the score helped retain interest during a scrappy match with too many untidy scums.
Knights opened brightly with Dougie Flockhart kicking an early penalty.
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Jersey, whose big pack caused Doncaster problems, came more into the game and drew level through fly-half Brendan Cope at the end of the first quarter.
Scrum-half Michael Heaney lifted the crowd with a blind-side break from a scrum in his own half and fed Flockhart whose subsequent kick ahead was chased all the way to the line full-back Paul Jarvis.
Cusack sent wing Tyson Lewis racing down the middle of the pitch with a slick inside pass but the move broke down when his long pass failed to find Flockhart.
With Otto cooling his heels in the sin bin, Knights finished the half on top but couldn’t add to their tally and it remained 3-3.
Knights made the early running at the start of the second half and Heaney, who started the move after the ball flew out of a scrum in the Jersey 22, was on hand to touch down near enough for Flockhart to convert after centre Andy Bulumakau, who impressed standing in for the injured Will Hurrell, had been held just short.
When Flockhart made it 13-3 on 50 minutes Knights looked to be on their way.
Even a well-worked converted Jersey try two minutes later didn’t seem to unduly worry Knights, who went close to a second try on a couple of occasions prior to Flockhart kicking a third penalty on the hour.
Jersey took the lead for the first time on 64 minutes with a close-range converted try by flanker Gary Graham.
Flockhart restored Knights’ lead on 67 minutes but Jersey weren’t to be denied and a sustained driving maul created the position for Otto to crash over from close range.
Doncaster Knights: Jarvis, Flockhart, Bulumakau, Clark, Lewis; Cusack, Heaney; List, Hunter, Quigley, Challinor,Hotson, Makaafi, Hills, Stedman. Rep: Veikoso, Sprotson, Pasquali, Phelan, Shaw, Humberstone,Field.
Ref: Michael Hudson (RFU)