Caroline Wozniacki has bid an emotional farewell to tennis following a third-round Australian Open loss to Tunisian trailblazer Ons Jabeur.

Caroline Wozniacki's career Age: 29

Age: 29 Nationality: Danish

Nationality: Danish Debut: 2005

Debut: 2005 Retirement: 2020

Retirement: 2020 Career prizemoney: $US35.233 million ($51.48 million)

Career prizemoney: $US35.233 million ($51.48 million) Grand slam singles titles: 1 — Australian Open, 2018

Grand slam singles titles: 1 — Australian Open, 2018 WTA Finals winner: 2017

WTA Finals winner: 2017 World number one for a total of 71 weeks (2010/11, 2011/12 and 2018)

World number one for a total of 71 weeks (2010/11, 2011/12 and 2018) Total WTA singles titles won: 30

Total WTA singles titles won: 30 Total WTA singles titles a finalist: 25

Total WTA singles titles a finalist: 25 Total WTA doubles titles won: 2

Total WTA doubles titles won: 2 Total WTA doubles titles a finalist: 2

A champion at Melbourne Park two years ago, Wozniacki choked back tears as she paid special tribute to her lifelong coach and father Piotr.

"I usually don't cry, so sorry, but these are the special memories that I will always cherish," said the former world number one.

"It's been a great ride. I'm ready for the next chapter. I'm really excited about what's next to come."

Revered as one of the fiercest fighters women's tennis has ever seen, Wozniacki landed her only Grand Slam crown in Melbourne with an epic victory over Simona Halep in 2018.

Before that, she had made the final of the US Open in 2009 and 2014, losing to Kim Clijsters and Serena Williams in respective years.

Caroline Wozniacki broke through for her first Grand Slam singles title at Melbourne Park in 2018. ( AP: Dita Alangkara )

The Danish player had foreshadowed her retirement with an Instagram post last month, where she said she wanted to start a family with her husband, former NBA player David Lee.

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Wozniacki also wants to raise awareness about rheumatoid arthritis, an autoimmune condition that can cause pain and swelling in the wrist and other joints.

She announced she had the condition in October 2018.

"It was only fitting that my last match would be a three-setter, a grinder, and a forehand error," she said.

"I've been working on those things my whole career. I guess this was just meant to be," the Dane said after bowing out 7-5, 3-6, 7-5 on Melbourne Arena.

In backing up her first-round upset win over 12th seed Johanna Konta, Jabeur is through to the last 16 at a major for the first time in her career.

"I'm really happy, especially because this grand slam I usually lose first round," the 25-year-old said.

"I don't have much experience so I was nervous, especially in that last set.

Ons Jabeur reached the fourth round of the Australian Open with a win over Caroline Wozniacki. ( AP: Andy Brownbill )

"I'm really happy I played Caro — you're an inspiration to me and so many players.

"I was actually a little bit stressed about that. It's her moment and I don't want to take that away from her."

The only Arab player to have ever made a WTA Final, Jabeur will play giant-killing Wang Qiang on Sunday for a spot in the quarter-finals after China's 27th seed sent seven-time champion Serena Williams packing with a 6-4, 6-7 (2/7) 7-5 upset win.

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AAP/ABC