Brodie Kostecki has beaten the field by six tenths of a second in the final practice session before Qualifying at the Repco Bathurst 1000.

The Repco Supercars Championship leader spent the latter half of the hour-long session on top, but rammed home his advantage with a 2:05.1215s after the chequered flag to increase the #99 Coca-Cola Camaro’s margin to 0.6311s.

Team 18’s Scott Pye (#20 Toyota Forklifts Camaro) was best of the rest in Practice 4 on a 2:05.7526s, ahead of the Mustangs of Chaz Mostert, Cam Waters, Practice 3 pace-setter Matt Payne, and Anton De Pasquale.

Triple Eight Race Engineering’s Shane van Gisbergen ended up 17th after mistakes on multiple laps during his final run in the #97 Red Bull Ampol Camaro.

27 cars rolled out when pit lane opened at 13:05 local time but one was wheeled back into the garage, with Erebus Motorsport in no rush to dispatch the #99 Camaro which finished no worse than third in each of the first three sessions.

Pye set the fastest first flyer, a 2:06.6486s, before David Reynolds (#26 Penrite Mustang) clocked a 2:06.5218s next time around.

With almost 14 minutes elapsed, Thomas Randle (#55 Tickford Racing Mustang) moved the benchmark to a 2:06.4750s, but both Kostecki and team-mate Will Brown had reportedly just been dispatched on green tyres.

Brown (#9 Coca-Cola Camaro) did indeed go to the top but the 2:06.0104s which he set suggested that the track had become slower due to the increased sunlight.

Kostecki bailed out of his lap after running slightly wide at The Chase before De Pasquale (#11 Shell V-Power Mustang) went to second on a 2:06.2651s, then Waters (#6 Tickford Racing Mustang) on a 2:06.0458s.

When Kostecki came out for a second run, he notched up a 2:05.6178s to go almost four tenths of a second clear of the field in the 26th minute, before handing over to co-driver David Russell.

Feeney (#88 Red Bull Ampol Camaro) took over second position when, 10 minutes later, he set a 2:05.9675s.

About 10 minutes later again, he improved to a 2:05.9106s with a lap comprised of a slower first sector, personal best second sector, and new fastest third sector.

With five minutes remaining, the top three was still Kostecki, Feeney, and Brown, followed by James Golding (#31 Nulon Camaro) and Waters, with van Gisbergen in 11th.

As qualifying sims became more prevalent, van Gisbergen locked a brake and ran wide at Forrest’s Elbow after setting his fastest first sector of the session.

Next time around, he was personal best to the second sector but locked up and ran long at Murray’s Corner with the chequered flag out.

Meanwhile, De Pasquale, then Waters and Pye, had moved to second, before Mostert (#25 Mobil 1 Optus Mustang) jumped 11 positions to third on a 2:05.7924s.

Kostecki had hopped back into the #99 Camaro and, well after the chequered flag, stormed to that 2:05.1215s with the fastest first and third sectors of the session.

Golding ended up seventh, from Randle, Feeney, and Jack Le Brocq (#34 Truck Assist Camaro), with Brown 11th and Reynolds 18th.

Qualifying starts this afternoon at 16:15 local time/AEDT.

CLICK HERE for full Practice 4 results