Jamie Whincup put the Red Bull Holden Racing Team on top as he edged DJR Team Penske's Scott McLaughlin in second practice at Hidden Valley.
The six-time champion managed to clock an impressive 1:06.03s effort to move to the head of the times as the 45 minute reached its climax.
Whincup was fast out of the blocks having headed the times before his initial benchmark was surpassed by Erebus Motorsport's David Reynolds.
A flurry of fast times shook up the order in the final five minutes this saw McLaughlin light up the timing screens as he surged to the top.
His time was then threatened by Craig Lowndes who clocked a lap just 0.0091s shy of the Kiwi.
However, Whincup's final showing proved enough to end the session fastest with a 0.03s ahead of McLaughlin, while Lowndes was demoted to third.
“The car's good, we were obviously changing it up heaps,” said Whincup.
“We can't just sit on our hands and cruise around so definitely car's better, made an improvement after the test day, hopefully that continues on for the rest of the weekend but there was plenty of time for everyone. If we can find time, I'm sure everyone can.”
McLaughlin seemed to concur, suggesting that he drove beneath the potential of his Shell V-Power Falcon.
“The car's nice, I just over-drove it just trying to find the limit in areas and I probably over-stepped the mark,” said McLaughlin.
“(That's) what practice is all about and we'll push into tomorrow and learn a lot.
“The car's been fantastic all day in race trim and qual trim so just looking forward to tomorrow, really. I just want to get racing.”
Reynolds, who was fastest at the halfway point, dropped to fifth after Mobil 1 HSV Racing's Scott Pye fired in a lap good enough to rise to fourth in the final moments.
Pye had an engine drama during the session prior to his final green tyre run.
Brad Jones Racing's Nick Percat ran as high as second before finishing sixth in the pecking order ahead of Garry Rogers Motorsport's James Moffat and BJR's Tim Slade.
Reigning champion Shane van Gisbergen and Will Davison rounded out the top 10.
Championship leader Fabian Coulthard was 13th behind Lee Holdsworth and Mark Winterbottom.
Jason Bright finished the session in 17th after Prodrive successfully completed a repair on his Falcon following a crash in the opening session.
After topping opening practice Nissan Motorsport's Rick Kelly could only manage 16th, while Jack Le Brocq was the top wildcard runner in 27th spot.
Supercars will contest a final 45 minute practice session on Saturday at 0925 local time ahead of a 15 minute qualifying (1350) and a 42-lap race (1615).
Result: Virgin Australia Supercars Championship: CrownBet Darwin Triple Crown: Practice 2
1 | Red Bull Holden Racing Aust | Jamie Whincup | Holden Commodore VF | 1:06.0360 | |||
2 | Shell V-Power Racing Team | Scott McLaughlin | Ford Falcon FG/X | 1:06.0705 | 0:00.0345 | ||
3 | TeamVortex | Craig Lowndes | Holden Commodore VF | 1:06.0796 | 0:00.0436 | ||
4 | Mobil 1 HSV Racing | Scott Pye | Holden Commodore VF | 1:06.2419 | 0:00.2059 | ||
5 | Erebus Penrite Racing | David Reynolds | Holden Commodore VF | 1:06.3042 | 0:00.2682 | ||
6 | Holden | Nick Percat | Holden Commodore VF | 1:06.3043 | 0:00.2683 | ||
7 | Wilson Security Racing GRM | James Moffat | Holden Commodore VF | 1:06.3078 | 0:00.2718 | ||
8 | Freightliner Racing | Tim Slade | Holden Commodore VF | 1:06.3301 | 0:00.2941 | ||
9 | Red Bull Holden Racing Aust | Shane Van Gisbergen | Holden Commodore VF | 1:06.3500 | 0:00.3140 | ||
10 | TEKNO Woodstock Racing | Will Davison | Holden Commodore VF | 1:06.3895 | 0:00.3535 | ||
11 | Preston Hire Racing | Lee Holdsworth | Holden Commodore VF | 1:06.4067 | 0:00.3707 | ||
12 | The Bottle-O Racing Team | Mark Winterbottom | Ford Falcon FG/X | 1:06.4223 | 0:00.3863 | ||
13 | Shell V-Power Racing Team | Fabian Coulthard | Ford Falcon FG/X | 1:06.4252 | 0:00.3892 | ||
14 | Supercheap Auto Racing | Chaz Mostert | Ford Falcon FG/X | 1:06.5029 | 0:00.4669 | ||
15 | Monster Energy Racing | Cameron Waters | Ford Falcon FG/X | 1:06.5961 | 0:00.5601 | ||
16 | Sengled Racing | Rick Kelly | Nissan Altima | 1:06.6496 | 0:00.6136 | ||
17 | MEGA Racing | Jason Bright | Ford Falcon FG/X | 1:06.6882 | 0:00.6522 | ||
18 | Mobil 1 HSV Racing | James Courtney | Holden Commodore VF | 1:06.7988 | 0:00.7628 | ||
19 | Erebus GB Galvanizing Racing | Dale Wood | Holden Commodore VF | 1:06.8362 | 0:00.8002 | ||
20 | Team CoolDrive | Tim Blanchard | Holden Commodore VF | 1:06.8639 | 0:00.8279 | ||
21 | carsales Racing | Todd Kelly | Nissan Altima | 1:07.0128 | 0:00.9768 | ||
22 | Nissan Motorsport | Michael Caruso | Nissan Altima | 1:07.0306 | 0:00.9946 | ||
23 | Team Harvey Norman | Simona De Silvestro | Nissan Altima | 1:07.0362 | 0:01.0002 | ||
24 | Repair Management Aust Racing | Alex Rullo | Holden Commodore VF | 1:07.1376 | 0:01.1016 | ||
25 | Wilson Security Racing GRM | Garth Tander | Holden Commodore VF | 1:07.1395 | 0:01.1035 | ||
26 | Repair Management Aust Racing | Cameron McConville | Holden Commodore VF | 1:07.1484 | 0:01.1124 | ||
27 | GoGetta Racing / MWM | Jack Le Brocq | Nissan Altima | 1:07.2349 | 0:01.1989 | ||
28 | Drillpro Racing | Macauley Jones | Holden Commodore VF | 1:07.2685 | 0:01.2325 |