Caleb Ewan says he wants to race the world's best in the Tour Down Under

CALEB Ewan says he is going to the Tour Down Under "to race" the best after winning his second road title in three days.

Caleb Ewan takes out another win in the U23 Road race at the Road National cycling championships at Buninyong.

CALEB Ewan has declared he is going to next week's Tour Down Under "to race" the best in the world after winning his second MARS Australian road title in three days this afternoon.

Ewan won a sprint from six riders who went clear of the peloton in the closing stages of the 132.6km at Buninyong to add the under-23 men's road title to the criterium crown he claimed on Thursday night.

Ewan withstood relentless attacks up the final climb by riders desperate to unhinge him to avoid a sprint finish, and revealed he was cramping the final lap, but was simply too good when it mattered.

Caleb Ewan rides past the City of Ballarat town hall and goes on to win the race at the Russell Gould Road National cycling championships in Ballarat.

He won from Robert Power and Bradley Linfield.

"The last lap I was cramping so I was trying to keep as composed as I could so no one knew I was suffering, because if they did they would attack me more," Ewan said.

"It's really special because whether I like it or not this is my last under-23 national titles so to get both the wins is just, I can't explain it, it's such a good feeling that I can be a good road rider, not just a crit rider."

Ewan has signed a professional contract with Orica-GreenEDGE beginning in the second half of next season.

But next week he will make his WorldTour debut for wildcard team UniSA-Australia in the TDU in Adelaide where he is aiming for experience but goes there with ambitions to be competitive.

"It's going to be hard for me being a UniSA rider and not getting as much respect as Greipel and Kittel will have, and at the moment it's all for experience," he said.

"(But) I'm there to race and I'll do my best to get the best result I can."

A three man breakaway had 52 seconds on the peloton with two laps remaining when a six-man chasing group including Ewan reeled them in.

Robert Power, Harry Carpenter and Jack Beckinsale unleashed a fury of late attacks but when Ewan let fly with 200m to go, he was never headed and stormed to his second win of the championships.

"It's hard being marked all the time but I think a lot of guys didn't know if I'd be able to get over the hill," Ewan said.

"But there was a lot of good climbers who people were also watching, so it wasn't like the crit where I was the main guy to win, so it was a bit more free."