The 22-year-old sits just six points behind current leader and reigning champion Shane Byrne in the race for the riders' championship, with just two races remaining after this weekend.
Not even a crash in the first practice session could stop Lowes clocking the fastest time as his effort of one minute 38.702 seconds was half a second quicker than the second-placed Suzuki of PJ Jacobsen.
Byrne ended the session third with fellow title fighters James Ellison and Josh Brookes fourth and fifth, respectively.
There was nothing anyone could do about Lowes' blistering pace in the second session as the Lincoln-born rider came close to smashing the lap record after shaving almost seven-tenths of a second from his quickest morning effort.
He once again left a string of fellow title protagonists in his wake as potential champions Ellison, Ryuichi Kiyonari and Byrne were third, fourth and fifth with Jacobsen getting closest to Lowes' time for the second session running.