In front of a sold-out crowd of 60,000 McTaggart leapt to a new lifetime best, clearing 4.73 metres to claim the victory on a countback.
McTaggart won the event ahead of one of the strongest pole vault fields assembled this season including hometown hero Molly Caudery, the 2024 world indoor champion, and American Katie Moon, the 2020 Olympic Champion and the 2022 and 2023 World Champion.
The 4.73m vault eclipses her previous best of 4.71m, which she recorded just five days ago in Switzerland.
The height is also the World Athletics Championships "Entry Standard", all but securing her spot on Tokyo for the World Championships in September, pending official selection from Athletics New Zealand.
While four competitors cleared 4.73m, McTaggart was the only one do to so on her second attempt, with Moon, her fellow American Emily Grove, and Switzerland's Angelica Moser all requiring three attempts at that height.
Alongside McTaggart, the four remaining athletes all fell short of clearing the next height in the progression of 4.84m, leaving the Diamond League crown to McTaggart.
The Auckland-based vaulter has been training and living in Loughborough, in the United Kingdom, for several months while she competes on the European circuit.
The Diamond League circuit enjoys a brief hiatus over the next few weeks before roaring back in to life again on August 16 in Silesia, Poland.
