A mother and her seven-week-old baby were on a petrol station forecourt when an armed robber pulled a gun at the counter.
The pair were at the Torbay Mobil on Auckland's North Shore when the armed bandit demanded money.
"I was still in my car so I hopped in and was [about] to drive off when I realised what was happening."
The woman posted on a local social media group that a "brave young guy" pulled up behind her on the forecourt and chases the robber down Deep Creek Rd.