Nathan Derry was crowned winner if the 2019 Spalding Darts Open last week.
Ace thrower Derry got the better of leading local talent Scott Winners 6-4 in a quality final, earning himself the trophy and a cash prize of £250.
Williams, who will be competing at the 2020 BDO World Professional Darts Championship at Lakeside in January, collected £150 as runner-up.
The event attracted 45 entries, with players contesting a round-robin format in the early stages.
James Cole and Connor Arberry were the beaten semi-finalists.
Organiser Ian Tilley said: “I’d like to say a big thank you to the helpers on the day, especially Scott Williams.
“We hope to run the competition in the same format next year, with a date to be announced.”
