HESSLE GC overhauled Hornsea GC's imposing 14-shot lead in the final event at Driffield GC to lift the East Riding & District of York Alliance series trophy.
Their cause looked a hopeless one until assistant professional Dave Woodhead and eight-handicapper Brian Drake came in with an astonishing 11-under-par 59 in the event, which had been postponed from a week earlier.
With the best two scores counting, Hornsea's first two placed on the board were 72 and 73, but their third pairing produced a 68 to put the lead back in their hands, Hessle's second score having been a 68.
The first two scores for either side had produced an 18-shot swing in Hessle's favour, but nerves were jangling after Hornsea's third score was posted until Rod Shimwell (3 handicap) and Charlie Fountain (10) carded a 66 to give Hessle a one-shot overall triumph.
Woodhead and Drake's 59 was all the more amazing for the fact that they closed with five consecutive pars.
Eleven of the previous 13 holes had been birdied, with the players sharing the workload.
Drake provided two net birdies and Woodhead two gross birdies to put them four under after four holes.
Their momentum stalled slightly with pars at holes five and six, but Drake engineered two consecutive gross birdies which, with another from Woodhead at the ninth, gave them an outward score of 29.
Woodhead made it three on the spin for himself by birdieing holes 10 and 11 and did likewise at 13 after Drake marked down a net birdie at 12.
Hessle's men's captain Neil Muir said: "It was a fantastic result, all the better for it being so unexpected.
"The final day score of Woodhead and Drake was special, but my congratulations go to all the Hessle golfers who have played over the course of the competition and who have done their own bit to contribute to the win."