The magnitude 5.1 earthquake struck at a depth of 7 km about 5 km south of Te Aroha in Waikato at 5:39 am.
More than 20,000 people reported feeling shock in nearby areas, including Hamilton, Tauranga, Rotorua and Auckland.
It was followed by two magnitude 2.7 quakes in the same spot at 5:47 am and 5:51 am.
About 8,000 people reported feeling the first aftershock and about 4,000 said they felt the second.
Truck driver Darryn Phayer said his 25-ton truck swayed sharply during the first quake.
“The truck started shaking violently and I thought ‘oh what’s going on here’ but literally, before that, in the farmhouse across the road from the yard, a bunch of dogs started barking and I thought ‘Oh what upsets them’ and within a few minutes it was on GeoNet.
“[It] scared me to death, to be honest.”
It comes after a magnitude 3.9 earthquake struck the same area last week.
GeoNet said they were probably on the same error system.
The area last had a strong earthquake in 1972 with a magnitude 4.9 quake, GeoNet said.