The 7ft 9in (2.38m) high clock from the Golden Age of English clockmaking combines a year-going striking movement by the celebrated maker Daniel Quare (c.1647-1724) with a première partie brass, pewter and tortoiseshell boulle case inlaid with Berainesque designs.
It was last sold by Winchester dealer G.H. Bell (now Gerald E. Marsh Antique Clocks) in the early 1970s to the clock connoisseur from the Isle of Wight whose family offered it for sale.
The late owner had tried to sell it through Christie's in 1987, but it failed to make its reserve (it was bid to £78,000).
The estimate on August 7 - a sale timed to coincide with the influx of boating enthusiasts for Cowes Week - was £150,000-250,000.
It attracted competition from Gerald E. Marsh - as bidding reached £220,000 proceedings were interrupted as he spoke to his client - but the winning bid came from a private collector from the Isle of Man.
The price comfortably beats the £135,000 achieved by Tennants of Leyburn for a burr walnut longcase c.1740 by George Graham in July 2006.
The buyer's premium was 15 per cent.