Cameron Waters led the way in opening practice, smashing into the 2min05 bracket and proving once again the Prodrive cars will be fast at this year's Supercheap Auto Bathurst 1000.
Waters' time put him up there with the main game drivers' best yesterday, recording a 2min05.7220 late in the session.
Freightliner Racing's Luke Youlden also busted into the '5s' just 0.111sec adrift with a 2min05.833m in the car that set yesterday's lap record.
"It's absolutely amazing to be in the 5s, I was aiming for the 6s and to do a five is unreal - really happy with the car and looking forward to the race," Waters said.
"If I can match it with those [main game] guys, that's where I want to be."
Just one second separated the top 13 cars, with Russell Ingall home third in the Holden Racing Team Commodore.
Paul Dumbrell followed, with Marcos Ambrose - who looked racy for most of the 45 minutes - completing the top five.
"It feels pretty good, the track is in great condition ... the car has improved," Ambrose said after the 2min06.4332 lap. The last time he has recorded around Mount Panorama would have been in the '9s'.
"It's great to see fast cars around here, and I think we'll see a new record this afternoon."
While there were a few close moments in the 45-minute run, with Dumbrell having an off and Frenchman Sebastien Bourdais just glancing the wall at the Grate - it ran smoothly and showed there will be quick times around the Mountain this weekend.