Adelaide, Australia - Allan Davis of Australia lived up to his promise as he won Friday's stage and retained the ochre jersey for the overall leader at the Tour Down Under.

"If the chance arrives, I'll definitely have a crack, but the plan is to keep it simple," the 26-year-old had said on the starting line of the fourth stage over 143 kilometres from Burnside Village to Angaston.

And the chance did arrive: The Quick Step rider won, flashing over the line ahead of Thursday's stage winner, Rabobank's Graeme Brown.

"I'm ecstatic," Davis said. "The crowd has been amazing again. To have the jersey for three days is just amazing."

In provisional results, Spain's Jose Joaquin Rojas Gil from the Caisse d'Epargne team took third, followed by local hero Stuart O'Grady, the Saxo Bank rider.

It was Davis' second stage win in the six-day Australian classic, which was split wide open by crashes and gale-force winds in Thursday's carnage.

Germany's Andre Greipel was forced to retire after dislocating his shoulder when he crashed into a stationary police motorcycle at 55 kilometres per hour. It was one of eight retirements.

Greipel, 27, was the defending champion and race leader going into Thursday's stage. He will receive further treatment in Hamburg for injuries that were expected to keep him out of the sport for at least three months.

Seven-time Tour de France winner Lance Armstrong, in his comeback race after three years in retirement, finished in the bunch - as he has each stage.

Going into the 143-kilometre stage, the 37-year-old Texan was 29 seconds down on Davis and Brown in 39th place.

"This is still the first race back after a long time off, so I would be fooling myself if I thought I was going to pound people," Armstrong said. "It's been harder than I expected, but everyone in the race would share that."

Armstrong said his real focus was on next month's Tour of California and eventual participation in July's Tour de France.

"Me being here is all about my own expectations and reminding people that it's a long season and that it's been three and a half years since my last race," he said. "That's a long time."

He tipped either Davis or Stuart O'Grady as the likely winner when the 11th edition of the Tour Down Under ends on Sunday. (dpa)