One man pointed the sawn-off shotgun at the driver while another moved to open the car door. The driver did not stop, and sped off, leaving the two men on the street.
They ran off on foot and police officers caught them nearby. A loaded shotgun and a pistol were located nearby.
Police are still seeking the third person who was seen in the car at Clendon. No one was injured during the incident.
The two men are being interviewed by Counties Manukau police, before a decision is made on possible charges.
The member of the public who was threatened with the shotgun subsequently contacted police and is also being spoken to.