Chaz Mostert's bid for a second Bathurst 1000 is back on track, with his co-driver Lee Holdsworth proving a formidable force in the 161-lap race.
The Walkinshaw Andretti United pair's hopes of securing victory at Mount Panorama were dealt a major blow after Mostert suffered a left-wheel puncture on lap-49.
Mostert was forced to pit his Commodore, immediately sliding from a big lead to 12th.
The pair, who began from pole, took a giant lead before their fifth pit-stop.
But because of the tyre puncture, Mostert and Holdsworth have been forced to come up with a different strategy to the rest of the field.
Mostert's win at Mount Panorama came in dramatic circumstances in 2014, while Holdsworth is searching for his maiden victory on his 18th attempt.
Tickford flyer Cameron Waters and defending champion Shane van Gisbergen are the best placed to topple Mostert with 64 laps to go.
Waters has been the pick of the main drivers during the race, making up for a shaky start from his teammate James Moffat, who slid from third to 10th in the opening laps.
The Dewalt Racing Team 18 of Scott Pye and James Golding was the first entry to withdraw, after just three laps.
Co-driver Golding started the race but the Commodore was forced into the pits due to a steering problem and never returned to the track.
Erebus rookie Will Brown's maiden Bathurst 1000 as a main driver is destined to be a disappointing one after teammate Jack Perkins had steering issues.
The pair remain in the race but are four laps behind Fabian Coulthard, who is in 23rd spot.
Brown storming to provisional pole on Friday was one of the more unexpected storylines of the weekend, but he was penalised during the top-10 shootout for an Erebus team error.
