Daryl Impey has made Tour Down Under history and Richie Porte is the King of Willunga for the sixth-straight year.
Porte went clear with a kilometre left on the decisive 3km Willunga Hill climb to take out Sunday's last stage of the Tour.
Kiwi cyclist Patrick Bevin quickly dropped off the pace during the first climb, but was unable to make up any ground as he faded into the pack.
The New Zealander started on Sunday despite suffering several injuries in a crash 10km from the end of stage five.
He eventually finished in 41st position, five minutes and 34 seconds behind Impey.
Impey rode superbly to finish third, on the same time as the Australian cycling star, giving the South African the Tour title. He is the first back-to-back champion in the event's 21-year history.
It is Porte's first win at his new team Trek-Segafredo.
"Hats off to Daryl Impey for the win, but to win six times up Willunga is a great feeling," Porte said.
"I was presented the keys of the town (Willunga) this morning, so that's a nice honour.
"It's a great way to start the year with a new team, it's a great set-up."
Porte, the 2017 Tour winner, has been runner-up four times.
Impey dedicated the overall win to much-respected Australian Mitchelton-Scott teammate Mat Hayman, who ended his 20-year racing career when he finished
Sunday's 151.5km stage south of Adelaide.
Teammate Lucas Hamilton also played a massive role in Impey's overall win, pacing him for much of the last Willunga climb.
Impey started the day seven seconds behind race leader Patrick Bevin and Porte was 26 seconds off the pace.
As expected, the remnants of the day's breakaway were caught on the first of the two Willunga climbs at the end of the stage.
The main group containing Impey and Porte were just behind and the speculative Sky move was soon over.
It came down to a select group on the last climb and, with 1.3km left, Porte went on the charge.
He shook off Poels and crossed the line first at the Willunga summit.
Poels, who was runner-up on the stage, finished third overall at 17 seconds, while Bevin finished several minutes behind Porte.