The emerging South Australian star won the 2019 national under-23 criterium crown and backed it up with the under-23 men's road race title on Saturday afternoon.

Drizners and Sebastian Berwick broke away in the lead on the last of 12 laps and it was the former which was too good in the sprint to the line.

Queensland's Elliot Schutlz had led the field at the bell, but was caught and eventually finished eighth overall.

"I've got lots of emotions, really. I've been wanting this race for a long time - since last year actually when I was fifth," Drizners said.

"I was hungry to come back for more. The time trial didn't really go my way, the crit really didn't go my way and to bounce back, come out here and win was really special.

"When I rocked up today I just felt this fire in my belly, I was so focused and really drilled to get the win here."

To take up his new professional contract, Drizners had to withdraw from the national track academy, which could have led to an Olympics appearance in Tokyo.

The 20-year-old will head overseas to link up with Hagens Berman Axeon next month and felt that his current form had justified the biggest decision of his career to date.