Ashton (15) gave a precision display of hurdling when she scorched up the front straight at the Caledonian Ground.
After three flights of hurdles, she was half a metre in front of the field and she was not going to relinquish that lead.
''I felt confident after the heats but there was still a bit of pressure at the start,'' Ashton said.
''It was a good feeling when I got the lead and I just went for it after that."
Ashton won the New Zealand secondary schools junior girls title in 12.21sec, from Christina Ryan (Roncalli College, 12.41sec) and Maddy Spence (Columba College 12.42sec).
She had finished sixth in the same event last year and worked hard on the technical skills last winter.
Her coach Megan Gibbons was impressed.
''Christina has a lot of natural talent and rises for big meets,'' she said.
''She doesn't let too many things faze her."
Ashton, who won a silver medal at the New Zealand aerobic championships at Wellington in September, is also a keen horsewoman and a promising eventer.
Erin O'Brien (St Hilda's) took the lead in the second lap and quickly moved away from the field in the open girls 2km track walk.
''I was confident after that,'' she said.
''It feels pretty good to win like that."
O'Brien (15) has been race walking for only two years but she has learnt quickly under the technical tutelage of Julie Myers and the fitness work of coach Jim Baird.
She won in a time of 11min 41.50sec from Sarah Meikle (Avonside Girls, 12min 19.99sec) and Kerri Batin (Hagley,) 13min 02.48sec).
Holly Robinson (Taieri College) used experience she gained at the London Paralympics to dominate the AWD events, winning gold in the AWD amputee grade in the shot put (10.08m), javelin (30.31m) and discus (34.03m).
All three distances were New Zealand records.
Maddy Witchell (Queen's) won AWD ID titles in the long jump (3.41m) and the 100m (16.14sec).
The long jump was a national record.
Liam Smith (Lawrence) won titles in the AWD ID long jump (5.03m) and discus (27m).
They were both national records.
Kirsten Reid (Queen's) won AWD AMP sprint titles in the 100m (15.19sec), 200m (32.15sec) and 400m (78.04sec).
David White (King's) won the AWD 2km road race in 7min 35sec.
The Otago Boys' senior boys 4 x 400m relay team of Sam Watson, Zak Watt, Chris McNoe and Christian Blackie was first in 3min 33.01sec.
The St Hilda's senior girls 4 x 400m team of Natalie Hill, Erin O'Brien, Meg McKay and Caitlin O'Brien was first in 4min 10.96sec.
Otago athletes won 33 medals - 15 gold, 14 silver and four bronze.
Otago Gold medallists
Maddy Witchell (Queen's HS).
Liam Smith (Lawrence).
Holly Robinson (Taieri College).
David White (King's).
Erin O'Brien (St Hilda's).
Kirsten Reid (Queen's).
Christina Ashton (Queen's).
St Hilda's 4 x 400m senior girls relay.
Otago Boys' 4 x 400m senior boys relay.
