The Chiko-backed champion set a session-best 2:06.1820s on his 10th lap of the Mount Panorama circuit.

Despite being the final hit-out before qualifying, there was little in the way of a “happy hour” run with only a handful of drivers improving late.

Kostecki was among those who stayed in the pit lane late, content with his lap.

“We were trying to bide our time there and try and get the track conditions like it’s going to be for quali a little bit later,” he said.

“The car feels really good. It’s been really good all weekend in race trim. I was a bit surprised we ended up first, I didn’t really think I got the most out of it.

“We’ll tune a few things up and we’ll see how we go in quali. I think a ‘5’ is definitely available, I thought it was then, but it’s one of those things, it’s only practice.”

Cameron Waters was the best Ford Mustang in second, his 13th lap putting him 0.1636s behind Kostecki.

Triple Eight Race Engineering’s Broc Feeney was third ahead of Grove Racing’s Richie Stanaway who shot forward late in the session.

The biggest surprise packet was Brad Jones Racing driver Jaxon Evans, whose last lap put him fifth and 0.4563s behind the top time.

“It doesn’t get much better than that, green set of tyres, pretty low fuel and a lap around Mount Panorama,” he said.“

Really happy with how that session went, just trying to find our feet and working pretty hard on finding a nice balance for both Dean and I.

“Pretty happy to finish that session where we did, it’s a good building step for qualifying this afternoon.”

David Reynolds (Team 18), James Golding (PremiAir Racing), Will Brown (Triple Eight), Anton De Pasquale (Dick Johnson Racing), and Jack Le Brocq (Erebus Motorsport) completed the top 10.

An awesome team effort from Matt Stone Racing to get their cars back out onto the track after both cars suffered damage from separate crashes in Practice 3 👏👏#RepcoSC #Bathurst1000 #7Motorsport pic.twitter.com/YAbDxBNRmI

— 7Sport (@7Sport) October 11, 2024

Despite their earlier bingles in Practice 3, the Matt Stone Racing Chevrolet Camaros of Nick Percat and Cameron Hill got on track.

Percat got on track 20 minutes into the session while Hill took to The Mountain just short of halfway.

The session was relatively trouble-free, although The Chase proved to be a hot spot for cars running off the road.

In the closing minutes, Cooper Murray suffered a crash at the top of The Mountain.

It began with him going wide over the top of McPhillamy Park before short-cutting Brock’s Skyline.

Unable to slow down in time, Murray slid into the wall at the Dipper and caused damage to the left-hand side of the #888 Chevrolet Camaro.

Murray limped back to the pit lane where work began to repair the car in time for qualifying.

Qualifying for the Bathurst 1000 is scheduled for 4:15pm AEDT.

Results: Repco Supercars Championship Repco Bathurst 1000, Practice 4