"It's been a fantastic day today," Lowndes said. "Our car has been working extremely well. To be able to have good car speed is always a treat."
Lowndes' domination of the rural Tasmanian circuit came after a dirty day in practice on Friday.
The five-time Bathurst winner found himself on the grass and gravel several times as he struggled to find balance in his Commodore.
But he rebounded with his first back-to-back wins in more than two years, clearly relishing the moment.
Reigning series champion Whincup said Lowndes "blew everyone away today and deserves his wins".
With Lowndes dominant, the most exciting action of the weekend came in the Holden Racing Team garage, where a furious Will Davison confronted Courtney after a clash between the two ended Davison's first race. He accused Courtney of being arrogant, pathetic and targeting him.
Courtney countered, saying Davison was "probably regretting saying a few things he said and looks like a fool" after stewards chose not to penalise anyone over the incident.
"Poor dill, poor dill," Courtney said. "We're racing hard and he's gotten a little fired up after the race ... emotions are high, people say things they don't mean."
The Holden Racing Team driver maintains his series lead after a pair of third-place finishes.
In the second race, 19-year-old Kiwi Andre Heimgartner was unable to cash in on his fifth-placed starting position, running off the track at the hairpin turn four on the fourth lap.
Countryman Scott McLaughlin came back from the dead, with his Volvo pit crew replacing a busted engine that caused a DNF in race one, to claim ninth in race two.
Shane Van Gisbergen picked up a fourth and eighth in the two races and Fabian Coulthard had two 10th-paced finishes.
- AAP
