The Field Size rules apply to all Australian Races. As per our Rules:
1.3. Where there are 8 or more runners in a Race, a place bet shall be paid on first, second and third places. If you wagered on a Fixed place bet when the field had 8 or more runners and the field later reduced to 7 or less runners, first, second and third places will be paid, but deductions may apply.
1.4. Where there are 7, 6 or 5 runners in a Race, a place bet shall be paid on first and second places only. If you wagered on Fixed place before the field was reduced to less than 5, we will still pay out first and second places, but deductions may apply.
1.5. Where there are less than 5 runners in a Race, all betting shall be WIN only.