The Otago swimmer claimed silver at the world short-course championships in the 800m freestyle with her time of 8min 10.41sec on Wednesday night.
She shaved a massive 8sec off her personal best, breaking the Otago and New Zealand age group and Otago open records in the process.
It was a stunning international senior debut at 800m. She previously only competitively swam the distance at the Youth Olympic Games in 2018.
It was Fairweather’s second silver medal, and ninth record broken, at the Melbourne championships after winning silver in the 400m freestyle.
She also finished eighth in the 4x200m freestyle relay on Wednesday, alongside fellow Otago swimmers Caitlin Deans and Ruby Heath and North Shore’s Summer Osborne.
The team finished in a time of 7min 50.76sec, Deans (1min 57.14sec) taking 2sec off her personal best and Heath (1min 58.44sec) 1sec faster than her personal best.
Fairweather then competed in the 4x50m freestyle relay alongside Helena Gasson, Rebecca Moynihan and Emma Godwin yesterday afternoon.
The team placed fifth in its heat in 1min 38.45sec to break the New Zealand record and qualify eighth for last night’s final at 11.45pm (New Zealand time).
In the 200m butterfly, Esme Paterson came second in her heat, finishing in 2min 11.75sec, but was disqualified.
It was unclear why she was disqualified.
It was a heartbreaking end to her international debut and what would have been a personal best by more than 1sec if it had been allowed.
Deans will compete in the 1500m freestyle fastest timed final at 11.15pm tonight.
