V8 Supercar series leader Jamie Whincup inched further ahead of rival Craig Lowndes after claiming the opening race at Symmons Plains on Saturday.
The two Holden racers finished first and second as Lowndes managed to keep alive his championship hopes.
Holden Racing Team's Garth Tander produced a late pass on Ford's Will Davison to snatch third place.
Whincup went into the Tasmanian round with a 143 point lead over Lowndes with three rounds remaining and took the chequered flag by 8.7 seconds.
Whincup snared pole position but lost it to Ford's Mark Winterbottom when his Commodore got bogged down with wheelspin at the start.