Championship leader Scott McLaughlin has put his Falcon into the wall in practice, walking away unhurt but unsure ahead of the penultimate meet of the Supercars season at Pukekohe Park.

The 25-year-old looked shaken after an uncharacteristic error at his home circuit on Friday.

After topping the timing charts in the morning’s practice session, the DJR Team Penske man was fastest again during the early stages of their afternoon tune-up.

But McLaughlin looked for too much at turn two at the regional New Zealand circuit, losing control and locking up before spearing into the wall.

“I just overstepped the mark. Completely my fault,” he said.

McLaughlin reported to the medical centre but was quickly released, even though damage to his Falcon made it impossible to return for the rest of practice.

“It was a pretty big hit … it felt big but I can’t do much about it now,” he said.

“I’ve got to own it and get over it. I’m pretty disappointed in myself.

“I’ve given (my pit team) a whole heap of work they didn’t need so I give myself a kick up the arse.”

Despite the crumpled hood and damage to the car’s exterior, McLaughlin’s team is expected to have car No.17 ready for qualifying and racing on Saturday.

In his absence, Jamie Whincup was quickest on Friday with a 1:02.6575 lap, ahead of David Reynolds and Mark Winterbottom, who dropped a bombshell on Thursday night by announcing he was leaving long-term team Tickford Racing.

His destination in 2019 is unknown but his speed suggests the Ford man can be a factor this weekend.

The Pukekohe circuit, 50km south of Auckland, is notoriously tough for drivers and in windy conditions on Friday, several drivers struggled to stay on the tarmac.

As McLaughlin took up a broom to help out in the garage, his chief championship rival Shane van Gisbergen took a trip through the grass.

The session was red-flagged three times; for McLaughlin’s excursion, Andre Heimgartner’s loss of power in pit lane and Todd Hazelwood’s high-speed off.

Hazelwood ran out of control at over 200km/h but was slowed through a sand trap and was able to reverse out of trouble.

McLaughlin leads van Gisbergen by 14 points with the two races in New Zealand and two races in Newcastle remaining in the series.

The meet is effectively a two-man showdown given Whincup, in third place, is 419 points behind second-placed van Gisbergen.