The Nairobi outfit won the play-off 2-1 on aggregate having created a narrow first-leg advantage in east Africa last weekend.
It was the first time in 15 CAF away matches spanning seven seasons that the Kenyan club kept a clean sheet.
New Star, whose line-up included star striker Junior Ngongang, applied constant pressure throughout only to be denied by the visitors.
Goalkeeper Boniface Oluoch was constantly in action for Gor, who survived despite lacking suspended defenders Joash Onyango and Haron Shakava.
The Kenyans will discover Monday which three clubs they will face in the group stage when the draw is made at CAF headquarters in Cairo.
Among the sides they could face are trophy-holders Raja Casablanca of Morocco, who are likely to be among the top seeds.
Raja made hard work of eliminating minnows African Stars of Namibia, winning only 1-0 in Marrakech after the first leg had been drawn 1-1 last weekend.
The six-time CAF title winners had to wait 57 minutes for the breakthrough with captain and centre-back Badr Badoun nodding in an Abderrahim Achchakir free-kick.
Badoun was unlucky not to score again when he connected with a Zakaria Hadraf corner only to be denied by an outstretched Namibian leg.
An eventful second half for the Raja captain continued nine minutes from time when he was yellow-carded, and a player from each side was sent off during stoppage time.
Raja will be among three Moroccan representatives in the draw with Hassania Agadir and 2018 quarter-finalists Renaissance Berkane securing places Saturday.