Nick Percat ended up over a second clear of the field as Friday practice concluded at a drying Winton Motor Raceway.
After a day dominated by wet weather, the rain finally stopped ahead of the second 45 minute run.
With a dry line gradually emerging, the circuit was finally good enough for slicks following the resumption from a red flag stoppage with six minutes remaining.
Scott McLaughlin had been fastest at the red flag with a 1:32.86s on the wets before times improved by almost five seconds in a hectic sprint to the flag.
The top spot changed eight times in the final minutes, with Percat’s eventual 1:28.11s effort proving 1.1s clear of second best McLaughlin.
Percat’s effort continues Brad Jones Racing’s strong form at Winton that saw Tim Slade win both races 12 months ago.
David Reynolds ended up third in Practice 2 ahead of Fabian Coulthard, who fired off at Turn 1 moments after going to the top.
Cameron Waters, James Courtney, Michael Caruso, Jamie Whincup, Tim Slade and Lee Holdsworth completed the top 10.
Reigning Supercars champion Shane van Gisbergen ended up down the order in 14th - his session including a late touch from James Moffat at Turn 7.
"If he comes in and apologises it’s alright. If he doesn’t… I don’t know what it’s about," said van Gisbergen.
Moffat took a different view from the incident.
"I don’t think Shane saw me by the way he turned in on me," he said.
"I don’t think he did. It was no malice on my behalf.
"He probably doesn’t think that, but I think we’ll all get a bit of a laugh out of it at the end of the day.
"He gave me a one finger salute after all that, so I don’t think he was too happy about it.
"But if I meant to do it, I would have done a proper job and turned him around properly."
Despite the improved conditions, three red flags peppered the second session.
The first was called 15 minutes in when Macauley Jones ran wide onto the slippery Turn 6 exit kerb and rotated his Drillpro Holden into the gravel at the following corner.
Fellow wildcard Shae Davies was the next to come unstuck, finding the Turn 3 gravel aboard his MW Motorsport Nissan at the 30 minute mark.
BJR’s Tim Blanchard found trouble following the restart – the CoolDrive Holden requiring a tow after a spin at the exit of Turn 3.