The heartbreaking story behind the surprise win of Mirjana Lučić-Baroni at the Australian Open.

Rewind back to the late nineties and Croatian tennis player Mirjana Lučić-Baroni was smashing it. Literally.

By the age of 17 she had broken several “youngest player ever” records, including winning the first ever professional tournament she entered – the 1997 Croation Bol Ladies Open – then defending it the following year to make her the youngest player in history to successfully defend a title. She was 16 years old.

In 2000, following a series of “personal problems”, the then 18-year-old tennis prodigy disappeared from the tennis scene.

Yesterday she defeated USA’s Jennifer Brady in the Australian Open to reach her first Grand Slam quarter final in 18 years.

Getting into the QF like . . . . #lucicbaroni #AusOpen pic.twitter.com/yO5Yvguonp

— #AusOpen (@AustralianOpen) January 23, 2017

It’s been a long time coming.

Now, I’m not a die-hard tennis fan. I’ll flick on matches in the background during the Australian Open and Wimbledon, with my interest peaking towards the finals but I draw the line at staying up past 2am to see how a match ends.

I’d never heard of Lučić-Baroni until last night, making me firmly a bandwagon supporter. But last night, watching her sheer disbelief turn into mad excitement verging on tears – and THEN learning her incredible tennis journey – it was hard not to become her biggest supporter.

Which is exactly why I think everyone needs to get behind the 34-year-old during this Aussie Open finals.

Lučić-Baroni's back story is about a lot more than training and injuries and fall-outs with coaches.

The "personal problems" that saw her promising tennis career come to a dramatic pause started when she fled her native Croatia with her mum and four siblings to escape the abuse she says she received at the hands of her father, Marinko Lucic.

She told the New York Daily Times in 2006 the first time he hit her was when she was just five and a half years old and had lost a tournament to an older player.

Lucic-Baroni as a teen at Wimbledon. Image: Getty

"My father smacked me in the nose. I was bleeding all over the house," she said.

"I had no clue what was going on. I was in complete shock. After that it was pretty much the same old thing, all the time."

She recalled several other instances, including being beaten by a "heavy Timberland shoe" for 40 minutes when she was 14 years old and 'only' made it to the semi finals of a tournament.

When he allegedly threatened to kill her mother in 1998 - just before Lučić-Baroni made it to the doubles finals of Wimbledon - the family fled their apartment in the early hours of the morning and spent 19 days in hiding while they waited for political asylum and escape to America.

Listen: Mamamia Out Loud discusses the bad boys at the Australian Open. Post continues after audio.

Lučić-Baroni said her father took all but $23,000 of her earnings and was soon diagnosed with Post Traumatic Stress Disorder upon arriving in the US.

The battle didn't end there. Her relationship with IMG, the management agency she signed with in 1998 (and one of the most powerful in the industry), descended into a war of accusations and lawsuits soon after she fled Croatia. She accuses the agency of "using medication, mind games and willful deceit to sabotage her career".

"I had to take Wellbutrin [an anti-depressant medication], and it wasn't by my own will," she told the New York Daily Times.

Her attorney Kevin Ambler said he believed the damage done by IMG to her career to exceed US$10 million.

On @MCourtArena, #LucicBaroni nabs the first set v #Brady 6-4. She's one set away from her first Grand Slam QF in 1️⃣8️⃣(!) years. #AusOpen pic.twitter.com/oDM8CqxRu0

— #AusOpen (@AustralianOpen) January 23, 2017

"The trouble that I've been through, I wouldn't wish on my worst enemy," she told the New York Daily Times in 2006, when she started to make her comeback to competitive tennis - and was unable to afford the basic things a professional tennis player requires.

"There is nothing worse than knowing you can play and being healthy, and you are just watching because you don't have the money (to travel and hire a coach)."

It took another four years for Lučić-Baroni to win her first title since her return, taking out a $25,000 ITF event in Florida in April 2010.

Now she's just earned herself a place in the quarter finals - a stage players like Andy Murray and Novak Djokovic failed to reach this year.

With no Aussie single players (female or otherwise) left in the competition this year, I'm putting all my might behind Lučić-Baroni, keeping everything crossed she'll continue to go further and further.

And if she doesn't? She'll still be the player that got me to really, truly care about tennis this year as a fighting symbol of passion, skill, strength and sheer determination.