St Clare's College student Small won the women's 800 metres race in emphatic style at the Youth Olympics in Buenos Aires, continuing a stellar rise which also included her Commonwealth Games debut this year.

Coach Philo Saunders is confident the 17-year-old will thrive on the challenge of chasing a senior Olympic goal in Japan in 2020 and says her raw speed will make her a dangerous international competitor.

Small carried the Australian flag into the opening ceremony in front of an estimated crowd of 250,000 and then dominated her rivals when she got the chance to race.

She became just the third Australian to win track and field gold in Youth Olympics history and led a five-medal Australian charge on day eight of competition in Argentina.

Athletics Australia has already marked Small as an athlete to watch and picked her to compete at the Commonwealth Games on the Gold Coast as a 16-year-old.

Now she hopes her senior experience can propel her towards the world championships in Doha next year and the Olympics in Tokyo.

"I’m absolutely stoked to get here and get the gold," Small said.

"It hasn’t sunk in quite yet. This whole experience has been amazing, to be announced flagbearer and now see the Australian flag raised from on top of the podium with a gold medal – I’m so stoked.

"I was a little nervous coming off the heat run and coming in top ranked, but the crowd really got me going down the back straight.I could hear all the Aussies cheering their guts out, it was awesome.

"It’s been a big year with Commonwealth Games and Youth Olympics, but the big goal now is Tokyo 2020. I really think this is a great stepping stone into that. I’ll get back into training when I’m home and have a good season to keep working towards Tokyo."

Australia's medal haul on Sunday was boosted through silvers for hurdler Sophie White, high jumper Oscar Miers, trampoline athlete Jessica Pickering and international doubles tennis competitor Rinky Hijikata.

But Small was undoubtedly the highlight, winning Australia's fourth gold medal of the event and vindicating her pre-race favouritism.

The Youth Olympic race format was a two-stage competition, with the gold medal going to the quickest combined times over two races. Small won both stages and demolished a strong field with a time of 2:04.76 in the second race.

Small has been on the Athletics Australia radar since bursting on to the scene as a 15-year-old when she ran a remarkable 2:01.46 last year and then backed it up with an Australian under-20 record of 2:00.81 at the Commonwealth Games.

"The other thing about Keely is that she's just got such a level head," Saunders said.

"I think this is definitely the start of a special career. But you have to harness it as well, you don't want to burn out of lose that passion for the sport.

"That's the big thing for Keely - keeping it fun and just enjoying the sport, and soaking the moments up.

"She's a gifted athlete, we want to get her strong but she's good good, raw speed and we want to keep that. So the basic parts are getting stronger, faster and fitter, but at an age-appropriate level."

Small's win capped off a brilliant two days for Saunders as a coach after Michael Roeger set a T46 marathon world record in Melbourne on Sunday.

Roeger, who was born without the lower part of his right arm, now holds three world records in separate events in the 5000 metres, the 1500 metres and the marathon. He sliced more than three minutes of the previous marathon world record.

"We went in with a good plan and stuck to it ... he'll look to London next year and the goal is to go under 2:20 and win a gold medal," Saunders said. "It's been a pretty good year to get those three world records all in the same year."