The Frank Wylie-coached Downing followed in the footsteps of Queenstown backstrokers Jodi Ford, Ellie Ferguson and Sophie Gibson who have excelled at national championships over the past seven years.
Downing won gold medals in the 100m (1min 10.99sec) and 200m (2min 27.96sec) backstroke in the girls aged 14 grade at the New Zealand age-group, division 2, championships at Moana Pool that ended on Saturday night.
She swam personal-best times by 3sec in the 100m and 7sec in the 200m.
The 200m was especially significant because it earned her 535 Fina points and ranks her 10th on the Fina list from the age 13 to 15 at the championships.
Any score over 500 points is significant in this age-group.
Downing's 50m splits for the 200m were 33.99sec, 37.23sec, 38.95sec and 37.85sec.
"It was a relief to know that my training has finally got me something in swimming," Downing, a pupil at Wakatipu High School, said.
Ryan Mawhinney (Queenstown) won a silver medal in the boys aged 14 200m butterfly in 2min 30.47sec. It was a personal best-time by 8sec.
It was a successful championship for Otago swimmers who won 25 medals - seven gold, nine silver and nine bronze.
Olivia Gold (13), a member of Andy Adair's Waves squad, won a gold medal in the girls aged 13 50m butterfly in 31.48sec in her first national championships.
Gold also won bronze medals in the 100m (1min 03.71sec) and 200m (2min 19.42sec) freestyle events. The 100m freestyle was worth 513 Fina points.
Ben McMahon (Neptune) won his gold medal in the boys aged 13 backstroke in 1min 08.46sec. He also won silver in the 50m (31.83sec) and 200m (2min 28.40sec).
Otago's other gold medal at the weekend was won by Luke Nie (Kiwi) in the boys aged 13 100m butterfly (1min 09.55sec). He also won silver medals in the 50m (30.86sec) and 200m (2min 31.72sec) butterfly events.
Anna Lindsay (Waves) claimed a silver medal in the girls aged 13 800m freestyle in 10min 06.54sec.
It was worth 509 Fina points.
Sydney Cook (Alexandra) gained a silver medal in the girls aged 13 200m butterfly in 2min 45.51sec. It was a personal-best time by 9sec.
Cook also secured bronze medals in the 50m freestyle (29.43sec) and 400m individual medley (5min 50.42sec) and the 50m butterfly (32.08sec).
Other bronze medals claimed by Otago swimmers were: Alice Moran (Neptune), girls aged 13, 50m (34.22sec) and 100m (1min 12.27sec) backstroke; Sam Wardhaugh (Waves), boys aged 13, 200m freestyle (2min 14.20sec).
The star of the championships was Canterbury's Laura Biddiscombe (Jasi) who won seven gold medals in the girls aged 16 to 18 grade.
She completed her haul with wins in the 100m individual medley (1min 10.23sec), 100m butterfly (1min 09.21sec) and 50m freestyle (28.46sec).
Stuart Smith (Hokonui, Gore) won gold medals in the 50m freestyle (26.02sec), 100m (1min 01.92sec) and 200m (2min 22.62sec) butterfly events in the boys aged 16 to 18 grade.
In the 50m freestyle he was part of a rare triple dead-heat with Sean Glasgow (Papatoetoe) and Caleb Te Kahu (QE2).
Topping the Fina points list from the age of 13 to 15 were Caitlin Bulman (Fairfield, Hamilton) in the girls aged 14 800m (9min 43.05sec) with 573 points, Amy Coulton (Nelson) in the same event with 563 points and Erin Evans (Pukekohe) in the girls aged 15 800m (9min 47.76sec) with 560 points.
The leading clubs were Swimzone Racing 1070 points, Wharenui (Christchurch) 933.50, Pukekohe 865, Jasi (Christchurch) 737.50 and Wanganui 535.
Neptune was the top Otago club in 23rd place with 244 points. Waves was 28th (203), Alexandra 41st (120) and Queenstown 45th (109). A total of 79 clubs competed at the championships.
