The 20-year-old ran 12.86sec to take 0.02sec off her national para-100m record when finishing second in the open women's 100m at the NQSF student games and all-comers championships.
She also managed third in the open women's long jump with a distance of 5.38m.
Otago athletes also claimed first and second in the open women's javelin.
National record-holder Tori Peeters won with a throw of 47.59m, while Holly Robinson was second in 41.12m.
Peeters had only one attempt after suffering a shoulder injury during the warm-up. The injury was nothing major but she pulled out of the competition as a precaution. She is expected to compete on Friday night.
Jess Hamill was the only competitor in the women's seated shot put and threw 7.37m.
Grimaldi, Robinson and Hamill are beginning their preparations for next month's world para-athletics championships, while Peeters is preparing for the World University Games.
