West Australian Astra Sharma overcame fellow Australian Priscilla Hon in a three-set thriller in stifling conditions.

Sharma, who is making her Grand Slam debut, won 7-5 4-6 6-1 in a match which took more than two hours. 

It is the 23-year-olds fourth win in less than a week after qualifying for the event and now pockets $85,000 for making it to the second round. It's double than her career earnings to date. 

"Today was obviously really hot, but been doing my recovery, and I feel ready for the next round already. I think just the adrenaline,” Sharma said.

"This is obviously the best I have ever done. That was mostly just relief that I got that (match point), because I respect her a lot, and I knew if I didn’t put her out soon, it could just turn around.”

It wasn't a great day out for Hon, with the Queenslander requiring medical assistance in the third set after telling an official she “threw up a little bit”. Her temperature and blood pressure were checked before a doctor was called.

For wildcards and main draw debutants Kim Birrell and Zoe Hives, both picked up significant scalps in their opening round straight set victories. 

Hives took just 61 minutes to oust former world No.30 6-1 6-2 while Birrell beat Spanish qualifier Paula Badosa Gibert 6-4 6-2.

It's another memorable win for Southport junior Birrell, who saw off world No.10 Daria Kasatkina at the Brisbane International. 

Fellow Australian Ellen Perez wasn't so lucky, going down to China's Yafan Wang 6-4 6-0.