UNDERSTRENGTH holders Calne surrendered their grip on the Wiltshire Senior Cup as Harlequins gained revenge for defeat in last season's final.
The Lilywhites were without five players, but had the better first-half chances, Jordan Roberts forcing a save from Heath keeper Grant Porter and Dan Lardner firing wide.
The visitors eventually took the lead 10 minutes into the second half as Rory Worthington, Levi Cox and Roberts combined to set up Lardner.
But Bemerton were level on the hour as Eddie Perrett scored after Kris Beasley had lost possession.
Twenty minutes from time, Seb Dawes' solo run ended with him firing past keeper Steve Allison.
Beasley had a shot saved as Calne pressed for an equaliser, but Jack Slade ran through the defence to wrap it up for Bemerton.
MORE FOOTBALL REPORTS, REACTION & PICTURES IN THURSDAY'S GAZETTE & HERALD