The Darwin Cup was canceled after a female jockey died from injuries following a fall near the finish of the sixth race on Monday.
Darwin Turf Club chairman Brett Dixon said Simone Montgomerie fell from her mount, Riahgrand, and sustained ''traumatic injuries'' in the home straight.
The 26-year-old Montgomerie was treated by doctors at the scene before being taken by ambulance to Royal Darwin Hospital.
''It is with great regret that we were advised by the family that Simone passed away shortly after arriving at the hospital,'' Dixon said. ''Stewards agreed it was best to abandon the meeting in order to begin an investigation into this tragic event.
''As far as the Darwin Turf Club is concerned, she was our family, and we're all devastated by this accident.''
Montgomerie was a seasoned jockey who had been racing in the Northern Territory since 2010 and domestic media reported that her 27 winners in the last season made her the premier jockey in the northern Australian province.
Her father, Peter Montgomerie, trained 2005 Melbourne Cup runner-up On A Jeune.
Adam Giles, the Northern Territory's chief minister, said Montgomerie ''was a champion jockey at the top of her game and a pioneer of women in racing who will be sorely missed.''
''This is a sad day for the Australian racing industry,'' Giles said.
The accident happened only two days after the National Jockeys Celebration day was held by the National Jockeys Trust, which provides support for families of riders who have been killed or injured in racing accidents.
National Jockeys' Association general manager Des O'Keeffe said the organization would support Montgomerie's family and offered counseling to other jockeys.
''It is unbelievable that this has happened just two days after National Jockeys Celebration day around the country,'' he said. ''I have had many jockeys ring me and they are absolutely shattered.''