Junner is a member of the respected Shitokai Karate Club at Renfrew Leisure Centre and now tops the World Karate Federation female under-21 rankings.
The 19-year-old won bronze at the World Championships in 2019 and took silver medal at the European Continental Championships last year.
She’s following in the footsteps of mum Lesley Anne and dad Douglas who are both black belts.
Junner, from Barrhead, said: “The more I trained and took part in tournaments, the more I began to realise I could achieve something in the sport.”
Niamh’s coach Terry Connell said: “It’s an incredible achievement for Niamh to be ranked No 1 in the world and we’re very proud of her.
“As a club we provide a training regime that can take people to the elite end of the sport, but also give people of all levels of ability the opportunity to keep fit and enjoy themselves through karate.”
Dad Douglas said: “She’s gone from a wee girl who could hardly kick and punch properly to become the world No 1.”