Chaz Mostert has set the pace in a practice session which came to an early end after Richie Stanaway slid into the wall at a rainy Winton Motor Raceway.

Tickford Racing’s Mostert (#55 Supercheap Auto Mustang) was fastest in the only session for primary drivers before Armor All Qualifying for the 13th race of the Virgin Australia Supercars Championship at the Truck Assist Winton SuperSprint.

Fabian Coulthard (#12 Mustang) was the biggest name to miss the top 10 ahead of knockout qualifying as the Shell V-Power Racing Team driver was denied any chance to improve his time due to the late red flag.

With the track still wet off the racing line, Stanaway’s #33 Boost Mobile ZB Commodore got away from him at Turn 6 and he slid into the tyre wall in the final two minutes of the 40-minute session.

The Kiwi, who had a recent test at Winton cut short due to neck pain, was able to extricate himself from the car despite the sizeable impact.

Scott McLaughlin (#17 DJR Team Penske Mustang) was second by 0.2253s to Mostert’s 1:19.6424s, having held first position for much of the period following the first red flag of the hit-out.

Lee Holdsworth, who in fact caused that stoppage, regrouped to end up third in the #5 The Bottle-O Mustang, while James Courtney was first of the Holdens with a 1:20.2984s in the #22 Mobil 1 Mega ZB Commodore.

Rick Kelly was fifth in his #15 Castrol Altima, while the Red Bull Holden Racing Team entries of Shane van Gisbergen (#97 ZB Commodore) and Jamie Whincup (#88 ZB Commodore) were sixth and eighth respectively.

They were split by the second Walkinshaw Andretti United entry of Scott Pye (#2 ZB Commodore), while Cameron Waters made it three Tickford cars in the top 10 in ninth, a spot ahead of former Tickford man Mark Winterbottom.

Mostert was hesitant to read too much into the results but was nevertheless pleased with his efforts.

“Adam (De Borre, engineer) was lucky enough to give me enough time in the session; he’s pretty good at that, he’s generally got a good structure around the session and sometimes it’s a bit better to go a little bit early, be a little bit out of sequence and get your lap in than not. Very lucky,” said Mostert.

“At the end of the day, you don’t know who is exactly the quickest guy out there.

“It was pretty daunting out there with a one-car line and it’s still a bit wet in some other areas too.

“Overall, we’ll still take that as a positive, pretty good rollout, we’re through to the second session (second part of qualifying) so we’ll take that.”

The session started on a wet track and the majority of cars were sent out on wet tyres, which were the optimal choice for the first 15 minutes.

Mostert spent the majority of that quarter-hour on top of the timing screen and got as low as a 1:31.4616s on wets before Winterbottom, who started on slicks, took the Irwin Tools ZB Commodore to a 1:30.9245s.

Those who were on treaded tyres then began to make the switch and for the next few minutes the benchmark was being lowered by several drivers per lap as an obvious dry line formed.

Waters (#6 Monster Energy Mustang) was fastest at 1:23.2586s when a red flag was called due to Holdsworth having spun between Turns 3 and 4 and backed Car #5 into the gravel trap.

After a brief delay, shortened by Holdsworth in fact being able to drive himself out of the kitty litter, David Reynolds (#9 Penrite ZB Commodore), Tim Slade (#14 Freightliner ZB Commodore), and then McLaughlin shot to the top.

The championship leader found more improvement before and after Mostert set what would prove to be the fastest lap of the morning, which saw rain fall on and off at the rural Victorian circuit.

Winterbottom bumped former team-mate Will Davison (#23 Milwaukee Mustang) out of the top 10, while Coulthard, who was ultimately 14th, revealed that he had already been set back by a drama with his Mustang.

“Bit of a bugger. We went out on a set prior to this one and the boys didn’t quite tighten the wheel up properly, we had a loose right-front wheel,” he explained.

“We lost a bit of time in that, but the car’s good; it was good in the wet, it was good in the dry, but unfortunately with Stanaway putting it in the fence we weren’t able to do the time there at the end.”

Reynolds was 12th and wildcard Jack Smith (#4 SCT Logistics ZB Commodore) 21st, while Jack Le Brocq (#19 Truck Assist ZB Commodore) brought up the rear of the 25-car field.

Armor All Qualifying for Race 13 starts at 1310 local time/AEST.

Results: Practice 1