Bates beat Dunlop Super2 Series leader Kai Allen by 0.1090s with relatively late hot lap in the 20-minte hit-out at the Reid Park Street Circuit.
The skies were slightly cloudy and the tailwind on Boundary Street (pit straight) was weaker than on the day before when pit exit opened at 09:30 local time.
Race 1 winner Jack Perkins (#79 Blanchard Racing Team S550 Mustang) was quickest after the first flyers on a 1:15.5793s before Allen (#1 Eggleston Motorsport ZB Commodore) took over top spot next time around on a 1:15.2426s.
A red flag was called in the sixth minute when Elliott Cleary (#19 Brad Jones Racing ZB Commodore) ran into the Turn 3 run-off area and became stuck there.
Meanwhile, Eggleston was changing pads and rotors on the Cooper Murray car which had been rebuilt following a big crash in Race 1 after he reported a long brake pedal in the #88 ZB Commodore.
He was among those to roll out when pit exit opened again, as team-mate Allen was shipped on greens, but several others were waiting in the lane.
Max Vidau (#17 Anderson Motorsport S550 Mustang) moved the benchmark to a 1:15.1981s before he was bettered by Cameron Crick (#38 Eggleston ZB Commodore) on a 1:15.0019s.
Allen crept back up to second on a 1:15.0089s but looked to have rolled out of it in the final sector, and certainly did so next time around after locking the rears at Turn 2.
Jordyn Sinni (#54 Eggleston ZB Commodore) took over top spot with a 1:14.6707s before Jarrod Hughes (#118 Image Racing ZB Commodore) edged him with a 1:14.6576s.
Perkins climbed back to second on a 1:14.6667s before Hughes improved to a 1:14.6065s.
Allen looked as though he may have been held up by Zane Morse (#11 AIM Motorsport S550 Mustang) when he could only creep forward to a 1:14.9827s which saw him remain seventh.
Next time through, though, the 2023 series winner vaulted back into provisional pole with a 1:14.5761s.
WAU had been among the teams to wait until the final minutes of the session for their green tyre runs, and Bates put the #25 ZB Commodore on top with a 1:14.4671s.
He pitted next time around and was followed into the lane by Allen, while Hughes had already put his cue in the rack.
They remained the top three, with Tickford Racing’s Brad Vaughan (#5 S550 Mustang) fourth on a 1:14.6229s, from Campbell Logan (#2 WAU ZB Commodore), Perkins, Sinni, Murray, Vidau, and Rylan Gray (#55 Tickford S550 Mustang).
Notables further back include Kelly Racing’s Aaron Camero (#27 S550 Mustang), who is second in the series standings, in 16th position and Crick in 17th.
The field was down to 24 after the #111 AIM S550 Mustang was withdrawn following brake failure in Race 1 which saw Dean Fiore thump the barriers at Turn 2.
Race 2 of Round 3 starts this afternoon at 13:15 local time/AEST.
Results: Qualifying for Race 2
Pos | Num | Team/Sponsor | Driver | Car | Cls | Fastest lap | Split |
1 | 25 | Walkinshaw Andretti United | Zach Bates | Holden Commodore ZB | DS2 | 1:14.4671 | |
2 | 1 | Eggleston Motorsport/Coca-Cola | Kai Allen | Holden Commodore ZB | DS2 | 1:14.5761 | 0:00.1090 |
3 | 118 | Image Racing | Jarrod Hughes | Holden Commodore ZB | DS2 | 1:14.6065 | 0:00.1394 |
4 | 5 | Dormer HVAC Racing | Brad Vaughan | Ford Mustang GT | DS2 | 1:14.6229 | 0:00.1558 |
5 | 2 | Walkinshaw Andretti United | Campbell Logan | Holden Commodore ZB | DS2 | 1:14.6523 | 0:00.1852 |
6 | 79 | Shaw and Partners Racing | Jack Perkins | Ford Mustang GT | DS2 | 1:14.6667 | 0:00.1996 |
7 | 54 | Eggleston Motorsport/Car City | Jordyn Sinni | Holden Commodore ZB | DS2 | 1:14.6707 | 0:00.2036 |
8 | 88 | Eggleston Motorsport | Cooper Murray | Holden Commodore ZB | DS2 | 1:14.6790 | 0:00.2119 |
9 | 17 | Anderson Motorsport | Max Vidau | Ford Mustang GT | DS2 | 1:14.7173 | 0:00.2502 |
10 | 55 | Tickford Racing | Rylan Gray | Ford Mustang GT | DS2 | 1:14.7270 | 0:00.2599 |
11 | 92 | RM Racing Cars with Coca-Cola | Cameron McLeod | Holden Commodore ZB | DS2 | 1:14.7280 | 0:00.2609 |
12 | 6 | AWC | Lochie Dalton | Ford Mustang GT | DS2 | 1:14.7503 | 0:00.2832 |
13 | 9 | Coca-Cola Racing | Cody Gillis | Holden Commodore ZB | DS2 | 1:14.7760 | 0:00.3089 |
14 | 11 | AIM Motorsport Australia | Zane Morse | Ford Mustang GT | DS2 | 1:14.7858 | 0:00.3187 |
15 | 99 | Erebus Motorsport | Jobe Stewart | Holden Commodore ZB | DS2 | 1:14.7978 | 0:00.3307 |
16 | 27 | Schramm Group Racing | Aaron Cameron | Ford Mustang GT | DS2 | 1:14.7980 | 0:00.3309 |
17 | 38 | Eggleston Motorsport | Cameron Crick | Holden Commodore ZB | DS2 | 1:14.8110 | 0:00.3439 |
18 | 15 | AWCON / MWM | Cody Burcher | Nissan Altima | DS3 | 1:14.8123 | 0:00.3452 |
19 | 19 | Brad Jones Racing | Elliott Cleary | Holden Commodore ZB | DS2 | 1:15.1616 | 0:00.6945 |
20 | 3 | Spitwater / MWM | Thomas Maxwell | Nissan Altima | DS3 | 1:15.1842 | 0:00.7171 |
21 | 22 | Kelly Racing | Mason Kelly | Ford Mustang GT | DS2 | 1:15.4196 | 0:00.9525 |
22 | 20 | Gtechniq | Reuben Goodall | Holden Commodore ZB | DS2 | 1:15.6058 | 0:01.1387 |
23 | 18 | Cavalier Homes | Matthew Chahda | Holden Commodore ZB | DS2 | 1:15.7937 | 0:01.3266 |
24 | 33 | Ascot Demolition/Cylinder Head | Callum Walker | Holden Commodore ZB | DS2 | 1:16.8306 | 0:02.3635 |