Race of Attrition at Mount Panorama
In a race of attrition, the Jamie Whincup/Craig Lowndes/Toni Vilander Ferrari and Van Gisbergen/Maro Engel/Craig Baird STM Mercedes have asserted their authority.
Regularly team-mates in Supercars, Van Gisbergen and Whincup did each other no favors as they traded paint down Conrod during an epic duel during the sixth hour.
Van Gisbergen, in a Mercedes that lacks the straight line speed of its rival, eventually got the better of Whincup, whose Ferrari is being run by a Triple Eight-assisted Maranello crew.
The fight between the two cars briefly turned ugly in the fourth hour when Baird turned around race leader Lowndes on a Safety Car restart.
Baird, seemingly unaware that no overlapping is allowed prior to the control line, dived to the inside of Lowndes at Murray's Corner, spinning the Ferrari into the gravel.
Critically, Lowndes was dragged out of the sand without going a lap down, while Baird also remained on the lead lap despite a 10 second stop-go penalty.
The Maranello Ferrari had recovered from a drive-through of its own in the opening hours following a Safety Car restart infringement from Toni Vilander.
Keeping a watching brief on the Whincup/Van Gisbergen battle is the Ice Break Porsche, which is being co-driven by Van Gisbergen's Pirtek Enduro Cup partner Matt Campbell, World Endurance Champion Marc Lieb, American Patrick Long and Australian David Calvert-Jones. The Porsche sits third behind Vilander and Baird with four hours remaining.
Prodrive team-mates Chaz Mostert and Mark Winterbottom are enduring tough days in their respective MARC and BMW Team SRM M6s.
Mostert led the bulk of the race's opening stint before handing over to Max Twigg, who subsequently tagged the wall in The Esses, dropping the car well down the order.
Winterbottom's BMW meanwhile runs six laps down in 16th place after struggles with power steering issues required a trip to the garage.
Garth Tander's #75 Audi also suffered misfortune, tagged into a spin by the Ice Break Porsche on a restart at the end of the third hour.
The Audi, which had Chris Mies at the wheel, was subsequently collected by the MARC Mazda of Garth's wife Leanne, causing significant damage to both cars.
Todd Kelly's Nissan GT-R sits 10th after eight hours, with the GT debutant having earlier held out Whincup during a stint in the lead during the fifth hour.
Team-mate Michael Caruso's chances were dashed within minutes of the race getting underway, co-driver Alex Buncombe pitting with a vibration.
The #23 GT-R, which was among the pre-race favorites, later underwent a gearbox and diffuser change and has spent much of the last four hours in the garage.
Of the Pro-Am entries, David Reynolds had the #61 Mercedes in the top 10 before striking mechanical trouble during the sixth hour.
Lee Holdsworth's #9 Audi sits seventh while the #11 McLaren co-driven by Tim Slade is 39th after suffering electrical issues.
Former Supercars champions Mark Skaife and Russell Ingall are meanwhile out of the race following a crash for the latter at The Dipper deep in the sixth hour.