The Cadia East mine has reached the propagation of Panel Cave 1 through to the surface.
The move was carried out ahead of schedule.
This propagation connects the broken rock off the cave to the surface, cutting production risk and increasing draw flexibility, Newcrest said in a company statement.
Commenting on the milestone, Newcrest CEO Sandeep Biswas said experience gained in the development of the Ridgway sub level cave and block cave, and the Telfer sub level cave has "led to the successful achievement of this critical milestone of the project ahead of time".
Cadia East is no focused on the propagation of Panel Cave 2 and the connection of the two caves.
The mine, Australia's newest gold mine, officially opened in May this year.