Although she has qualified for this month's Australian Open in Melbourne, Dokic was not as successful in her first main draw match since last August, falling 5-7 7-6 (7-3) 6-1 to 81st-ranked Julia Schruff of Germany.
Unseeded Schruff won the contest in one hour and 56 minutes after Dokic's service game fell apart and double faults mounted up, allowing the German to take the deciding set in just 20 minutes.
Returning to Australia after turning her back on her adopted homeland in 2001 to represent Serbia and Montenegro, Dokic had been scheduled to play on Monday but the match was rained off.
Dokic, who had not played a tournament since last August and a WTA Tour event since last May, was using the Auckland tournament as a build-up to the Australian Open which starts on January 16.
She is also playing at the Canberra Classic next week.
Second seed Daniel Hantuchova of Slovakia makes her first appearance at the tournament when she meets Yulia Beygelzimer of Ukraine later on Tuesday.
Third seed Elena Likhovtseva, fourth seed Maria Kirilenko and Japan's seventh seeded Shinobu Asagoe are also on court later in the day.