John Constable's Flatford Lock on the Stour towards Bridge Cottage has set a new world record for a sketch under 10 inches by the artist.
The work sold for £869,000 ($1.1m) to top Bonhams' Old Master Paintings auction in London on December 8 - almost trebling its £300,000 high estimate.
Constable produced the sketch as a study for Landscape: Boys Fishing
Constable (1776-1837) produced the piece as a key study for Landscape: Boys Fishing, which is now in a state of disrepair at Anglesey Abbey.
The fact it was unknown to Constable experts (having resided in a US private collection for more than 70 years) added to the excitement surrounding the lot.
Andrew McKenzie, Bonhams' director of old master paintings, said: "There was a huge amount of pre-sale interest in Flatford Lock on the Stour looking towards Bridge Cottage, reflected in an intense bidding war during the auction itself.
"Although the picture has undoubted art historical importance, it is first and foremost a beautiful painting - a Constable masterpiece in miniature - and I am not surprised that this exquisite work commanded such a high price."
Constable's work is hugely in fashion, with his peaceful scenes of rural Suffolk offering respite from today's more hectic life. His auction record stands at £22.4m ($33m), set by The Lock in 2012.
The auction also featured a strong performance of John Cleveley the Elder's depiction of ships arriving at Harwich. The 18th century work sold for £112,500 ($141,750).