Offered at The Cotswold Auction Company's June 21 sale in Cheltenham, it was discovered by the auctioneers' Lindsey Braune among house contents that had descended from an old local farming family.
It was entered with an estimate of £5000-7000, but numerous commissions, including a bid from the US, plus interest from the room and the phones on the day ensured that level was left far behind.
The final duel was down to the specialist London pottery dealer Garry Atkins, who was in the room bidding on behalf of a collector, and a phone bidder, with the hammer falling to Mr Atkins at £82,000 (plus 17.5% buyer's premium).
The price is testimony to how much the best English delftware can still make if it ticks all the boxes and this was a blue-chip piece with everything in its favour.
The market-fresh piece, which was probably made in one of the delft factories at Southwark, is inscribed, dated, painted with the arms of the Worshipful Company of Salters and the initials WWR and bears the legend I am but earth it is most trew, disdain mee not for so are you, Ano dom 1674.
Lindsey Braune had contacted the livery company hoping to find a clue to its provenance, but unfortunately their records began a few years too late to throw any light on its original owner.
Equally key to the mug's attraction was its market freshness, large size - a substantial 6½in (16.5cm) high - and fine state of preservation, with just a few nibbles and a chip around the rim.
"It was exceptional, I have rarely seen a piece of that age in that condition," Mr Atkins told ATG after the sale.
The price is a house record for the auctioneers.
By Anne Crane