Australian golfers Scott Arnold, Brett Rankin and James Nitties are in a four-way tie for the lead at the midway point in Auckland.
Kiwi Josh Geary shot a seven-under-par 65 in his second round to be level with the Aussie trio on 11-under-par.
One stroke back is two-time champion Michael Hendry, fellow New Zealander Mark Brown and Frittelli.
Tjaart van der Walt and Rourke van der Spuy missed the cut.
The New Zealand PGA Championship is a tier two event on the PGA Tour of Australasia.