The Quins came out on top in this closely-fought local derby with Linden at the Volunteer Park.
With Linden having won twice at Wilton Lodge Park earlier in the season, in League and Shield, it was the Quins’ turn to win away from home.
Kirk Ford kicked an early penalty for the home side before being yellow-carded. Adam Hall slotted the goal for Quins.
Steven Anderson missed a penalty for the Royal Blues, as did Ford when he returned, leaving the scores tied 3-3 at the break.
Into the second half, Quins took a quick tap and Ross Nichol crossed for a try.
Hall missed the conversion, but slotted a penalty.
With 11 minutes to go, Ford narrowed the gap with a three-pointer.
However, Harlequins nicked the match as scrum half Mark Young went blind and dived over in the corner for the clinching score.