Jonker, who is a reputed climber, was well supported in Saturday's 100 km road race and Sunday's Criterium Mountain Circuit by his European Once teammate and fellow Aussie Neil Stephens.
Both Once riders are among the the five European-based Australian cyclists who will race in the Tasmanian tour which starts today (22/1).
Stephens was unlucky on day one, after having battled gale force winds to lead the 63 strong pack to the base of Mount Buller, punctured and fell behind on the climb.
But his strong work set up Jonker's winning break as he moved away on the 16 km climb up the summit.
The stage had to be reduced to 100 km from 160 km after a heavy storm ravaged the course. Riders had to battle very strong cross winds for most of the stage.
A the mountain climb began to break up the peleton, Jonker and German Crish Nierman broke way with Australian international Steve Hodge chasing hard.
The very sheer final 500 metre climb to the finish line gave Jonker a 1 min 13 sec gap on Nierman.
On Sunday, the riders raced over a 1.4 km Crit circuit with Stephens playing a blocking role for Jonkers. Stephens allowed the recent Skilled Bay Cycling Classic winner David McKenzie of Victoria to break away early, but he was overtaken, first by teammate Tristan Priem and then by the final winner Glen Mitchell from New Zealand.
Mitchell won by 100 metres from Jonker, who took the overall title with 28 points. The mountain circuit was very tough although the distance of the race was 25 kms.
1. P. Jonker (SA) 20 points 2. G. Neirman (Ger) 16 3. S. Hodge (ACT) 12 4. M. Tuck (Vic) 10 5. P. Pape (Vic) 8 6. N. Gates (NSW) 6 7. C. Presser (Germany) 4 8. N. Dahlberg (NZ) 2
1. G. Mitchell (NZ) 10 points 2. P. Jonker 8 3. Henk Vogels (Vic) 6 4. E. Hollands (WA) 5 5. C. Denham (NSW) 4 6. S. Hodge 3 7. Neirman 2 8. Kelvin Martin (NSW) 1
1. Jonker 28 2. Neirman 18 3. Hodge 15 4. Mitchell 10 5. Tuck 10