Holden's James Courtney climbed from 16th on the starting grid to finish second with another Prodrive driver, David Reynolds, coming home third.
Courtney, who had crashed into teammate Garth Tander in the past two events, would have given his garage heart palpitations when the pair tussled again late in the 70-lap race.
Thankfully, Courtney was able to get through cleanly this time and went on to pass Reynolds for his runners-up finish.
Holden's Fabian Coulthard, who started the race in second position on the championship, suffered a drive-through penalty after spinning his wheels before being released during a pitstop.
That penalty forced the Brad Jones Racing driver back in the field. He eventually finished 13th.
Volvo's Scott McLaughlin also suffered heartache, snaring his first pole of the season but being forced to retire after just 21 laps because of a mechanical failure.
Holden's Craig Lowndes, who started the race a lowly 23rd, regained second on the championship standings with his ninth-place finish but conceded a stack of points to Winterbottom.
Lowndes' teammate and defending series champion Jamie Whincup is still without a win since March but will take heart from a fifth-place finish.
Despite what is easily his best finish for a while, Whincup trails Winterbottom by 391 points and his chances of defending his title appear to be all but over.
The next event is at Queensland Raceway in Ipswich from July 31 to August 2.
Championship Points
1. Mark Winterbottom (Ford)1465
2. Craig Lowndes (Holden)1217
3. Fabian Coulthard (Holden)1205
4. David Reynolds (Ford)1192
5. Chaz Mostert (Ford)1183
- AAP
