Racing for Avanti, Haig will be striving to cut the 11-second buffer that Tour leader Simon Clarke has going into the 124km final at Arthurs Seat on the Mornington Peninsula.

Saturday's racing was a 156km duel from Mitchelton Winery to Nagambie.

South Australia's Robert-John McCarthy, racing for the Australian under-23 team, achieved the biggest victory of his road racing career.

McCarthy outsprinted many of his highly-fancied opponents to win stage three in the 61st edition of the tour.

Haig still leads the the race for the best under-23 rider in the classic.

The young gun jumped from 20th in the standings to third after Friday's 163km battle from Ballarat to Bendigo.

Eaglehawk's Glenn O'Shea, a world champion on the track, is eighth overall and 1.23 behind Clarke.

Drapac Pro Cycling team-mates, Lachlan Norris from Barkers Creek and Darren Lapthorne from Bendigo are in 14th and 17th place at 1.28 and 1.31 behind the tour leader.

Horsham's Mark O'Brien, also racing for Avanti, is 28th at -1.48.

The tour's top 10 going into Sunday's final leg:

Simon Clarke, Cameron Wurf -8, Jack Haig -11, Nathan Haas -1.09, Neil Van der Ploeg -1.21, Jonathan Cantwell -1.21, Glenn O'Shea -1.23, Cameron Meyer -1.23, William Clarke 1-23.

The race for the Sprint King crown is being led by John Anderson from Drapac.

Thomas Hamilton is leader in the battle for the King of the Mountain title.

Orica-GreenEDGE leads the race for the teams title from Avanti -6, Cannondale -12, and Drapac at 1.20.

Sunday's stage at Arthurs Seat starts at  2.30pm and will finish about 5.30pm.