Seumas MacKay defied the odds to take home the gold medal in his debut outing in the under-18 national vest.
The 16-year-old athlete from Dunrossness ran a winning time of 1:54:07 in the 800m at the Celtic Games in Dublin on Saturday.
He led a field containing the best runners from Ireland and Wales from start to finish, despite being a year younger than the age limit.
Coach David Wagstaff, who has trained MacKay for around 18 months, hailed “an absolutely fantastic result and a great time”.
MacKay followed his 800m success with a silver medal in the 4 x 400m after running a strong second leg.
In June, MacKay ran a personal best time of 1:53:32 to win gold for Shetland at the island games in Gotland.