Hill took advantage of an opening-lap puncture from pole-sitter Dale Wood to grab a lead he would never lose, surviving a mid-race restart and pressure from Nick McBride and Cooper Murray.
Wood led the field on the opening lap, however a slow puncture saw him spin off the road at Turn 13 and ultimately forced him to pit.
Murray climbed to third on the second lap, with Aaron Love also passing David Wall, who found himself turned around at Turn 3 a lap later.
A mid-race Safety Car to recover a stranded Indiran Padayachee closed the field up, negating Hill's lead.
Murray attempted to pass the Porsche Centre Melbourne entry shortly after the restart but couldn't find his way through; the leaders all caught by Wall, who recovered to fourth.
Hill ultimately won the 45-minute encounter by under a second, McBride a season-best second and Murray continuing his title-leading form in third.
On his Porsche Payce Carrera Cup Australia debut, Craig Lowndes ran as high as sixth after qualifying 11th.
Stephen Grove finished 10th to claim ProAm class honours.
Carrera Cup switches to sprint mode tomorrow with the second race of the weekend scheduled to start at 14:55 local time/AEDT.