Grimaldi finished with a personal best time of 12.20sec to set an Oceania record at Stade de France.
She lowered the record of 12.23sec she set in the heats last night (NZ time).
It marks the two-time Paralympian long jump champion’s first medal on the track at the Paralympics.
Ecuador's Kiara Rodriguez won gold in 12.04sec and Brittini Mason, of the United States of America, won silver in 12.10sec.
Grimaldi won back-to-back bronze medals in the 100m at the world para athletics championships in 2023 and earlier this year.
The 27-year-old will now compete in the T47 long jump on Friday at 8pm (NZT).
24-year-old Will Stedman (Christchurch) produced an outstanding display in the men's 400m T36 last night to record a national record time of 52.92, behind defending champion James Turner of Australia who set a world record mark of 51.54.It was the fifth Paralympic Games medal of Stedman's career and his third successive Paralympic Games medal in the men's 400m T36 after winning bronze at both the Rio 2016 and Tokyo 2020 games.
Anna Steven finished eighth in the women’s T64 200m final with a time of 29.37sec.