Brisbane, QLD, 31 December 2018 | AAP / tennis.com.au

Australian wildcard Kimberly Birrell toppled world No.10 Daria Kasatkina in a three-hour test of nerves in the first round of the Brisbane International.

The 20-year-old daughter of a Gold Coast tennis coach rallied from 3-5 down in the third set to win 5-7 6-4 7-6 (3) on Monday.

SHE'S DONE IT!

QUEENSLANDER Kim Birrell (World Number 283) causes a major upset against the World Number 10 Daria Kasatkina at the Brisbane International!#UpsetAlert #BrisbaneTennis #9WWOS #Tennis pic.twitter.com/BUTyRAkPma

— Wide World of Sports (@wwos) December 31, 2018

She will be joined in the second round by Melbourne qualifier Destanee Aiava, who dominated proceedings against Kristina Mladenovic to win 6-3 7-6(2) and complete a perfect start for the Australian contingent.

Aiava has now won four consecutive matches in Brisbane, her latest against a former world No.10.

“I think the momentum of playing three matches in a row (in qualifying) helped me today, instead of having a break,” she reflected.

“I felt pretty good on the court. Mentally I thought I stayed with her really well. I’m really happy to get the win today.

“I’m actually loving being out here, playing my third Brisbane (main draw). I think being tough and loving the challenge has always been in my background so that really helps a lot.”

Birrell, meanwhile, had won the Australian Open Play-off final earlier this month to secure a spot at January’s Grand Slam and maintained that form against the highly-fancied Russian Kasatkina.

Dropping an early break in the third set and then losing her serve at 3-4 wasn’t enough to deter the Queenslander, who unleashed a series of crushing backhands to break twice herself and serve for the match at 6-5.

Kasatkina broke back, but the 283rd-ranked Birrell played a fearless tiebreaker to claim the biggest scalp of her career in a battle that lasted three hours and eight minutes.

“I’m in shock. I can’t believe it,” Birrell said on court.

“Thank you so much to everybody for coming out and supporting me – I really couldn’t have gotten through that without you. I was so close to cramping in the end. Just using your guys’ energy and you really got me through.

“It’s so important to stay positive and believe in yourself. I just left it all out there. She’s an unbelievable player – I’ve looked up to her for a really long time. I knew it was going to be a very physical match.

“To have my first top-10 win where I train every day at my home means the world, and I will never forget this moment.

“I’m so glad I get to play again.”

Ukraine’s Lesia Tsurenko had an easier time of it in her first-round clash with Mihaela Buzarnescu, prevailing 6-0 6-2.

She will play Birrell in the second round, while Aiava meets US Open champion and second seed Naomi Osaka.