After a semi final jury performance on Thursday – which wasn't aired to the public - and today's live audience show, the 28-year-old has triumphed by proceeding to the grand final.
Serbia, Moldova, Hungary, Ukraine, Sweden, Australia, Norway, Denmark, Slovenia and The Netherlands also made it through.
In a tight Semi Final at Lisbon's Altice Arena, the 28-year-old stepped up her game with a concert-like performance of her song, "We Got Love". Dressed in a purple one-shoulder shimmering dress, the Darwin-born starlet oozed confidence on stage and encouraged her fans to sing along.
"It was nerve-wracking, but the crowd is undeniable," she says in a post-show conference. "I felt that love from the crowd and that's what my song is all about."
Upon hearing she had made it through to the grand final, the singer reveals, "I felt like my heart was about to jump out of my body!"
"It's a huge thrill that people across Europe have taken "We Got Love" to their hearts," Jess said in a statement by SBS. "I am so excited and really looking forward to sharing the stage with some great artists in the Grand Final."
Watch Jess' stellar performance below.
The international press center also showed their support by clapping along to the music; the atmosphere was truly electric.
This is the fourth consecutive year Australia has made it to the Eurovision Grand Final. Dami Im was the closest competitor to victory when she placed runner-up in 2016.
Jess has previously performed as an international guest in 2014.
"The difference this time is that I'm competing," Jess says of returning to Eurovision.
"The competition is always changing. Bringing the song to life on the stage was beyond my expectations. And tonight, we've got love."
So with 26 countries vying for the title, who will win?
The Aussie faces stiff competition on the night with fellow competitor Cyprus' Eleni Foureira predicted as the likely winner.
Her non-stop dance track "Fuego" and daring costume raised the bar.
But Eleni's biggest competitors aren't far behind. As well as Australia, Sweden is a huge threat, while Denmark and Slovenia could be dark horses.
In the first semi final, Albania, Austria, Bulgaria, Cyprus, Czech Republic, Estonia, Lithuania, Israel, Finland and Ireland progressed to the grand final.
For Jess, however, the thought of winning Eurovision is far from her mind.
In a previous interview, the 'Fallin' singer explained how she is maintaining her cool despite being a strong contender.
"People have been saying, 'we want you to win', or 'you're going to be in the top five', and I try not to take much notice," she says.
"I'm so excited to be part of it all."
Meanwhile, host country Portugal and The Big Five - UK, France, Italy, Germany and Spain – have automatically qualified for the final event.
Below are the 25 countries competing in Saturday's Grand Final.
The Eurovision Grand Final airs at 5am on Sunday, May 13 on SBS and you can catch the encore at 7.30pm.