The half-hour session was a rare showing of strength from a range of Ford teams, with the Blue Oval locking out the top five spots.
Tickford's Cam Waters led the way early thanks to a 1m51.224s, before teammate Randle set an impressive benchmark with a 1m50.838s.
That proved unbeatable, although Grove Racing's Matt Payne did go close in the final minute, falling just 0.07s short.
"I really enjoy this type of track, it's reminiscent of a lot of the tracks I raced over in Europe, smooth and fast," said Randle.
"We're always pretty strong at [Albert Park] as well, very similar, high-speed. You really want to have a stiff car and smooth inputs, I think that works around here and it suits my style.
"[Engineer] Ray [Lau] has dialled the car in nicely and we've done a lot of work in the sim leading into this race as well, working on small things that I can work it. It helps when I roll out and I'm ready to go."
Will Davison was another later improver to end up third ahead of Waters and Anton De Pasquale.
Broc Feeney was the best-placed Camaro driver in sixth ahead of James Courtney, Andre Heimgartner and series leader Brodie Kostecki.
Van Gisbergen, meanwhile, ended the session dead last without a representative time.
The Kiwi was complaining of steering issues from the start of the session and, after several efforts to rectify the problem, was out of the car by the midway point.
Van Gisbergen has had similar issues earlier this season, although a chassis swap ahead of the Sydney SuperNight was thought to have sorted that out.
