Simon Gerrans has taken the Tour Down Under lead from fellow Australian cycling star Cadel Evans after stage five on Saturday.
Gerrans will take a one-second lead over Evans into Sunday’s final stage.
If he can hold onto the advantage, Gerrans will become the first three-time winner in Tour history.
He also took out the race in 2006 and ’12.
Compatriot Richie Porte broke clear in the last 2km of the Old Willunga Climb to win the 151km fifth stage south of Adelaide with a masterful ride.
Gerrans, who trailed Evans by seven seconds before the stage started, broke clear of the Tour de France winner along with second-placed Italian Diego Ulissi near the finish.
Porte won by 10 seconds from Ulissi and third-placed Gerrans, with Evans sixth across the line at 14 seconds.
Gerrans held the stage lead after winning stage one, but Evans took it from him when he soloed to victory in stage three.
The crucial stage predictably came down to the last of two climbs up Willunga.
Popular German Jens Voigt, who featured in a four-man break at the start of the stage, attacked again by himself with 8km left.
But he was caught at the foot of the 3.5km climb.
After a series of attacks and counter-moves between Evans and Gerrans, Porte went clear by himself with 2km to go.
Robert Gesink was fourth on the stage and Daryl Impey fifth, with those two on the same time as Evans.