Eighth-seeded Birrell outclassed fifth-seeded West Australian Astra Sharma 6-4 6-2 to earn her second grand-slam appearance, having previously received a wildcard in 2016.

Birrell's success came after the Queenslander felt like she "started from scratch again" after elbow surgery two years ago that led to her spiralling outside the world's top 1000.

"So many mixed emotions. It all hit me at the end because I knew she was going to put up a fight until the very last point, until we shook hands," the 20-year-old said.

"So I'm just so happy - there's so much joy. I've been waiting for this opportunity and I'm just so glad I could take it.

"I never take anything for granted but I was hopeful and, through every single training session, you always have to have goals and you have to dream big and that's what I've done.

"It's going to be incredible, come January, and I'm just super excited."

A graduate of the same Southport tennis centre that produced Samantha Stosur and Bernard Tomic, Birrell suffered a gallant 6-4 6-4 first-round loss to world No.9 Karolina Pliskova three years ago in her only previous Open start.

"During that AO, I played on Hisense Arena, one of the biggest courts in the world, so I'm definitely going to draw on that experience for sure," said Birrell, who has climbed back to No.288 in the rankings.

James Duckworth also crowned a comeback from serious injury with victory over former Australian Open and Wimbledon junior champion Luke Saville in a rain-interrupted men's playoff final.

Duckworth won 6-3 5-7 7-5 7-6 (7-2) after the long battle was suspended for 90 minutes by a flash storm.

Duckworth's win earned him a seventh main-draw berth at the Open and came after the 26-year-old underwent five rounds of surgery, mostly for foot injuries, over 12 months.

Australian Associated Press