Dyke (28) won the feature women's event in a time of 13.11sec into the teeth of a strong 4.9m-per-second head wind. She was followed home by Brooke Cull (Auckland, 13.18sec) and Laura McPhail (Hill City-University, 13.27sec).
Dyke, who won the title in 2012 but missed out last year because of injury, flew out of the blocks and had 50cm on the field at halfway.
But at 60m, she could hear Cull and McPhail coming up close behind her.
Dyke had only come back to racing last month and was not confident about her fitness.
''I could hear the other girls pushing me and I just tried to hold my form over the last 20m,'' Dyke said.
''I just had to stay in the moment.''
Ben Anderson (Caversham) ran a solid race to win the men's 800m in 1min 56.15sec from David Catherwood (Ariki, 1min 59.15sec).
Anderson (23) led from the start, passing the 200m in 28sec and the 400m in 58sec, and sustained this pace through the second lap to win comfortably.
''I just wanted to control the first lap and come home fast in the second,'' he said.
''It was a bit slower than I will have to run at the nationals.''
Anderson, a physical education student at the University of Otago, ran his best time of 1min 52.01sec in Wellington a year ago.
He showed last month he was not far off this time by running third in the Capital Classic at Wellington in 1min 53.46sec. Anderson is the third ranked senior man in New Zealand this year.
He is noted for his fast finish, which
gives him a chance of reaching the podium at the national championships in Auckland at the end of March.
Christina Ashton (Taieri) tried the higher 840mm hurdles for the first time and won the junior women's title in 16.65sec. She felt more comfortable in the 762mm hurdles and easily won the women's aged 15 to 17 title in 15.83sec.
Caitlyn George (Hill City-University) emerged as one of the most promising young sprinters in Otago when she won the women's aged 15 to 17 double in convincing fashion.
She sped away in the last 40m to win the 200m in 26.11sec from Ashton (26. 80sec) and the 100m in 12.90sec.
George (15), a boarder at St Hilda's, comes from Gore and won bronze medals in the junior girls 100m and 200m at the New Zealand secondary school championships in December.
Liz Wilson (Hill City-University) broke her own Otago masters women's aged 50 to 54 100m record by 0.07sec with her winning time of 13.38sec.
Wilson (50), who won the gold medal in the 400m at the world masters championships in Brazil last year, easily won her specialist event in 64.17sec and the 200m in 27.63sec.
Daniel O'Shea (Hill City-University) emerged as the top male sprinter when he won the three senior men's titles - 100m (11.34sec), 200m (21.90sec) and 400m (48.41sec).
Clubmate and last year's New Zealand junior champion Robert Jopp won the junior men's title in 50.50sec.
Sian English (Ariki), the New Zealand secondary schools road race champion, easily won the junior girls' 1500m title in 4min 39.73sec and the 3000m in a personal best time of 10min 10.92sec. She leaves Dunedin this week to study engineering at Auckland University.
Anna Grimaldi (Taieri), who won four gold medals in AWD events at the New Zealand secondary schools championships, broke her own New Zealand T47 under-19 200m record with a time of 28.54sec.
The Taieri 4 x 100m relay team of Nadia Lyders, Joccoaa Palmer, Leonie Palmer and Mikayla Thorn broke the Otago girls aged 14 record with a time of 53.94sec. The previous record was run by a Taieri club team in 1979.
In her first race back after knee surgery, Rozie Robinson (Hill City-University) won the women's 3km walk in 15min 29.67sec. Julie Edmunds (Caversham) was second in 16min 48.13sec.
