Mr Stewart, 66, shot a nett 131 over two days to claim the Aurigny-sponsored event ahead of Tim Butler, Peter Cunningham, Keith Allan and Andrew Adamson.
The 16-handicapper said playing alongside two youngsters helped him win - as did relying on a caddie who won last year's title.
Mr Stewart, who moved to Alderney six years ago after living in Zimbabwe, said: "I played with two young guys who are champions of the future and I think the recipe for winning must be to have a caddy in the group who was last year's winner."
Scottish-born Mr Stewart admitted feeling nervous down the stretch.
He said: "I got a little jittery towards the end of the round as I knew I was on for a good score but luckily I did enough to win."
The sun shone throughout the annual tournament, which attracted more than 100 competitors from around the world.
Players from the United States and Portugal took part, as did many from Guernsey, Jersey, England and Scotland.
Aurigny's managing director Malcolm Hart said: "Once again we've had a fantastic weekend. The weather has been fantastic and everyone has enjoyed the wonderful hospitality here in Alderney."
Mr Hart went on to reveal Aurigny would be delighted to continue sponsoring the event.
He said: "Aurigny would love to sponsor the event next year, so hopefully the committee will have us back."
The Guernsey Bereavement Service has made three visits to Alderney over the past few months and would like to continue to help you. We are visiting the island again on
Tuesday, 23rd February 2024 and would invite anyone who feels they would like Bereavement Counselling to telephone the Bereavement Service Office on 257778 to make a time to meet one of our counsellors.
The Guernsey Bereavement Service has made three visits to Alderney over the past few months and would like to continue to help you. We are visiting the island again on
Tuesday, 23rd February 2024 and would invite anyone who feels they would like Bereavement Counselling to telephone the Bereavement Service Office on 257778 to make a time to meet one of our counsellors. 