Kohler regains Tour lead

Swiss cyclist Martin Kohler has regained the Tour Down Under lead after Oscar Freire took out Friday's fourth stage in a sprint finish.

BMC's Kohler finished in the leading group of 40 riders on the 130km leg from Norwood to the Barossa town of Tanunda, near Adelaide, and holds a two-second lead over Australian Michael Matthews (Rabobank), who finished in the top five on Friday.

Overnight leader Andre Greipel of Lotto-Belisol slipped well behind the front group, eventually finishing more than seven minutes behind, effectively ending his chances of a third Tour title.

Greipel looked to completely run out of gas on the tricky Mengler's Hill climb 20km out from the finish and contenders Kohler, Matthews, Simon Gerrans and Matthew Lloyd took full advantage.

Defending champion Cameron Meyer also finished in the leading group while in more good signs for the Australian contingent, Rohan Dennis was the first to the top of the decisive climb.

For Freire it was his first win in Katusha colours and his first in almost a year.

"The finale was difficult. I knew I had a really good chance to win (the stage) on what was a very hard day's racing," Freire said.

The title will most likely be decided on Saturday's second-last stage with two laps of the famous old Willunga Hill climb to prove crucial.

To add to the drama, the stage will finish on top of the climb for the first time in the Tour's 14-year history before Sunday's final 90km street race, which is unlikely to alter the overall standings.