Kimberly Birrell's fairytale Brisbane International campaign has continued, posting a shock 7-6 (7-2) 6-2 win over Anastasia Potapova to secure a quarter-final berth and a ticket as Australia's new No.1 female player.
Just 24 hours after posting a stunning 7-5 7-5 win over world No.8 Emma Navarro, the wildcard took down world No.35 Potapova in 106 minutes in front of adoring fans at Pat Rafter Arena.
Birrell's career was on thin ice when an elbow injury cost her almost three years on tour.
It was during that time out the world No.113 worked as part of the media team at the Brisbane International.
But Birrell was the star attraction on Thursday, holding her nerve against a player ranked 78 places higher to secure a last-eight appearance at a WTA 500 event for the first time.
After the match, Birrell welled up as she recounted her tough journey back to full fitness.
"It's been a long road," she said.
"I have had a few injuries, but as does everyone who plays professional sport - everyone has their trials and tribulations in life.
"I've been super lucky to have such an incredible family and team behind me.
"They believed in me when I didn't even think I was going to get back on court.
"They encouraged me. They're pretty much the only reason why I'm back playing at this level today."
Birrell will take on world No.55 Anhelina Kalinina in the quarters after the world No.55 posted a 6-1 6-4 win over Yue Yuan on Thursday.
The latest heroics from Birrell have catapulted her to 99 in the live world rankings.
It means she will be Australia's No.1 female player when the next round of official rankings are released on Monday, edging her ahead of Olivia Gadecki, who has slipped to 104th in the live rankings following a poor United Cup campaign.
"I have much bigger goals than just reaching the top 100. I want to be comfortably inside the top 100," said Birrell, who is not yet guaranteed a spot in the main draw at the Australian Open.
Birrell was broken in her first service game against Potapova, but she quickly broke back and dominated the rest of the opening set without quite capitalising on a glut of golden opportunities.
The 26-year-old Gold Coast talent had break-point chances in the fifth, seventh, ninth and 11th games, but wasn't able to convert any of those eight opportunities.
Unforced errors proved Birrell's undoing for most of those chances, while three stunning winners from Potapova in the 11th game saved three break points on that occasion.
It was a different story in the tiebreak as Birrell produced a clinical display to race out to a 4-0 lead on the way to sealing the first set in 66 minutes.
Potapova's building error count proved costly in the second set as Birrell snared the early break and then broke again to cruise to victory.
"I'm totally speechless," Birrell said.
"I really believe in the way I'm playing and anything can happen, especially playing at home."
In other round-of-16 action, Polina Kudermetova upset third seed Daria Kasatkina 1-6 6-2 7-5, while Ashlyn Krueger defeated Suzan Lamens 7-5 6-0.
