Police received a number of calls from motorists and were en route to try to stop the wrong-way driver when the crash happened.
Ms Yong suffered extensive head-to-toe injuries in the smash and died in Auckland Hospital, he said. "Her next of kin made emergency plans to travel from Kuala Lumpur to be at the victim's bedside prior to life support being turned off. It's a tough pill for the family to swallow and this was a needless loss of life.
"The family are very close-knit, very quietly spoken. They're obviously very upset at the loss of their family member in New Zealand. It's a terrible time in their lives."
Alcohol was believed to be a factor in the crash and police had taken a blood sample from the driver, he said.
"We're waiting for her to recover in hospital ... we're hoping to speak to her soon. She has serious injuries herself."
Ms Yong was part of the east and south Auckland branch of Ceroc dancing.
This year she won first place in the over-45 category of the Auckland Ceroc Championships with dance partner Derek McEwan.
Close friend Peter Felhofer said Ms Yong's mother and sister were finalising funeral arrangements.