The Repco Supercars Championship leader put the paddock on notice by lapping the Californian road course within two tenths of the very best pace of the day, set by Team Penske‘s Ryan Blaney in a Ford Mustang.
Not only was Brown more than three tenths clear of his team-mates, with Austin Dillon 11th-fastest and Kyle Busch 15th on the timesheet, he was also the quickest Chevrolet driver of the day, 0.031s ahead of Hendrick Motorsports’ Alex Bowman.
The Toowoomban recapped his day with Speedcafe columnist and former Triple Eight Race Engineering boss Roland Dane, who is on the ground this weekend at Sonoma.
“No one would really say expectations but I think a lot of people were thinking, if we ran inside the [top] 20 then it would be a pretty good day,” said Brown.
“To run top three, I think they’re pretty excited.
“It’s still close times and you can’t make a mistake, so I’ve got to back it up tomorrow but I think everyone’s pretty excited.
“Hopefully, that’s what I’m, here for, to try and see if we can do a good job in the car for Richard.”
Brown found his way towards the top of the timing screen on each of his runs, sitting third-quickest after his third lap of the session and climbing to seventh on his second run.
“I felt pretty good straight out of the gate,” he recounted.
“I didn’t feel like I was going to crash or anything like that, so I was able to build into it.
“When I went P3, I could tell I was catching a few cars, I was gapping a few cars around me, so I thought we were running well.
“But, it was just about not crashing, not making a fool of myself out there, and running laps today.”
Fellow Supercars full-time Cam Waters ended up 35th in the 38-car field in RFK Racing’s ‘Stage 60‘ Ford Mustang.
Earlier, Shane van Gisbergen was quickest by more than three tenths of a second in Xfinity Series Practice, with qualifying for the second tier kicking off on Saturday at 15:30 ET/Sunday at 05:30 AEST.
Cup Qualifying starts 18:00 ET/08:00 AEST.
CLICK HERE for more from Will Brown with Roland Dane