Jersey were made to work hard against a well-drilled Premiership outfit that boasted a host of internationals.
The hosts got off to a flying start, scoring in the opening minute as Jersey were left reeling against a fast and accurate attack that saw Mike Brown provide the perfectly weighted grubber kick through for Charlie Walker to touch down; Marcus Smith converted.
Jersey got themselves into the right areas on a number of occasions throughout the half, but the Quins' pack were able to nullify any attacking threat from the lineout with an organised and powerful defence that prevented the Reds from getting a driving maul going.
Danny Care mixed up his game between box-kicking for position and interlinking with Marcus Smith who managed his back line well, and Francis Saili always looked threatening with the ball in hand.
Jersey were organised in defence, and with the ball in hand made telling runs into the opposition territory, notably by Argyle and Voss up front and Eastwell and Pincus in the backs.
The second score of the afternoon came through Mark Lambert after some sublime link up play from Rob Buchanan, Chris Robshaw and Danny Care; Smith again converted.
The half ended in disappointing fashion for the Reds. Having soaked up pressure on their own line that yielded a penalty, the clearance didn't make touch and the Quins wasted no time in charging back for a Marlon Yarde converted score to turn around leading by 21-0.
The second half started again in explosive fashion with the hosts crossing after just one minute. Saili broke through the Jersey defence before feeding Jack Clifford who in turn off-loaded to Yarde for his second of the afternoon.
Quins added a fifth through Smith following a Walker intercept, and their 6th by Jamie Roberts who scored with his first touch of the game when he crashed over, taking the ball from Care at a quickly taken penalty.
The Reds finally got just reward for their efforts and determination. Tom Pincus was excellent in the approach work before releasing Brendan Cope to score.
The game structure lost some shape with numerous replacements by both sides, before Jersey struck again from an untidy lineout deep in the Quins' 22. Apakuki Ma'afu was quickest to react to a loose ball, and barged his way over as the Harlequins' defence were caught napping. Cope converted.
As the game entered the final minutes, Jersey were again having to defend against sustained Quins' pressure when Pincus intercepted and galloped the length of the field to touch down and further reduce the arrears. Cope added an excellent conversion from wide to make it 40-21.
But the Quins weren't finished, and with the final play of the game Tom Visser got in on the action receiving the ball out wide and beating his man to score.
Following the final whistle Chairman Mark Morgan was full of praise for the squad. "It was a really good performance, and the first half score in particular really didn't reflect the run of play. Perhaps the telling difference was the way that their class showed as they capitalised on the opportunities when they came".
HARLEQUINS: Brown, Yarde, Marchant, Sili, Walker, Smith, Care, Lambert, Buchanan, Collier, Glynn, Horwill (capt), Robshaw, Ward, Clifford (YC 30).
Replacements: Boyce, Elia, Gray, Swainston, South, Merrick, White, Luamanu, Mulchrone, Lang, Roberts, Stanley, Visser.
JERSEY REDS: Van Breda (capt), Pincus, Best, Eastwell, Worrall, Bryant, Dudley, Woolmore, Saunders, Armstrong, Voss, Sexton, Rogerson, Joyce, Argyle.
Replacements: Macfarlance, Godfrey, Brodley, Quarrie, Bartle, Nagle-Taylor, Hardy, Cope, Ma'afu, Abrahams, Adair.
REFEREE: Adam Leal. Assistants: Roy Maybank, Simon Adams
ATTENDANCE: 4,400
Half Time: 21-0
SCORERS
Harlequins
Tries: Walker, Lambert, Yarde (2), Smith, Roberts, Visser
Conversions: Smith (5), Lang
Jersey Reds
Tries: Cope, Ma'afu, Pincus
Conversions: Cope (2), Van Breda