Bobby Ryan and Glen Crowe manufactured high-quality goals in the first half to send Shels on their way to a facile victory in their opening Setanta Cup clash.
The former Bohs duo lit up Tolka Park with magnificent strikes as Pat Fenlon's side completely subdued Glentoran to take an early lead in Group Two.
Ryan opened the scoring in the 30th minute with a screamer from 20 yards that flew past Elliott Morris, and the Glens keeper was equally helpless as Crowe lifted the ball over him from 40 yards six minutes later.
The Reds continued to dominate proceedings after the break as Crowe added a third with a close-range header on the hour mark.
