The aircraft, believed to be a Stoddard-Hamilton Glasair, came down in Macleans Reserve, Bucklands Beach, 15km east of downtown Auckland, about 2.45pm after losing engine power.
Fire Service northern communications centre shift manager Jaron Phillips said the pilot, the sole person on board, walked away from the emergency landing uninjured.
"He did a pretty good job. He basically belly-flopped it," Mr Phillips told NZPA.
"There was some minor damage to the plane's propeller and undercarriage but that's it." Police said the pilot chose the Macleans Reserve, which backs onto Macleans College and is next to the Eastern Beach area, because it was a sizeable reserve.
Witnesses said the landing spot was not far from the ocean's edge and about 100m from houses in the nearby suburb.
The pilot, who did not want to speak to reporters at the scene, was taken from the reserve by police after packing up some belongings from the aircraft.
