Cycling: Australia's Gerrans tied for lead in Tour Down Under

Australian cycling star Simon Gerrans and Spaniard Alejandro Valverde are tied for the lead after a riveting fifth stage of the Tour Down Under.

Unofficially, Gerrans has the race lead because he has a lower aggregate placing for the first five stages.

Valverde beat Gerrans by only a couple of centimetres at the end of stage five at Willunga, south of Adelaide.

The decisive Willunga stage finished at the top of the 3km Old Willunga Hill climb for the first time in the tour's 14-year history and the change was a resounding success.

Australian Nathan Haas broke clear on the first climb up the hill, but he was caught well before the second climb to the finish.

The stage came down to a selection of eight riders that included Gerrans and Valverde.

Gerrans had the better line going around the final left-hand corner only metres from the finish, but Valverde was able to jump around him to cross the line first.

This is the first race for Valverde since he ended a two-year doping ban, which was connected to cycling's Operation Puerto scandal in Spain six years ago.

Gerrans is the key rider in the Santos tour for the new Australian professional team GreenEDGE and their plan nearly worked to perfection.

The tour will now come down to Sunday's final stage, a 90km street race just outside the Adelaide CBD.

It will be only the second time in the tour's history that the time gaps have been this tight going into the final stage.

The last stage of this tour always ends in a bunch sprint and GreenEDGE will probably try to make sure that Gerrans finishes ahead of Valverde, wherever they are in the field.

Valverde is unlikely to be able to score bonus seconds at the intermediate sprints during the stage.

- AAP