Nagel will tackle next month's national crosscountry championship in Auckland.
Napier's Aniela Apperley finished second in the girls' 12 and under-2km race in Taupo with a time of 7m 49s. Clubmate Stella Marshall was ninth.
Napier's Ollie Marshall finished second in the boys' 14 and under-3km race in 10m 20s. Clubmate Mitchell Snell was fourth, six seconds behind Marshall.
Snell and Marshall consistently perform and provide each other with strong competition.
Napier's Steve Lindsay finished fourth in the masters men's 60-plus grade's 6km race while clubmate Claudia Layton was also fourth in her under-20 4km race in 17m 23s.
In his first attempt at the North Island champs, Napier's Lucas Duross was 10th in the senior men's 9km race in 30m 38s.
Regular rival and clubmate Kristian Day was 16 seconds behind in 11th place.
Auckland's Jono Jackson won the senior men's title in 28m 51s.
In the wake of these successes the Napier contingent should perform well at the Hawke's Bay/Gisborne champs in Gisborne on July 16.