In the final challenge, the beauties and their geeks were required to perform a couple's dance in the Magic Mike Live show in front of a live audience.
Also in attendance were this season's eliminated contestants, who guest judged their performances and ultimately voted on who would win the competition.
Josie, a professional dancer, was in her element during the challenge which saw contestants perform a routine on a wet circular stage.
Josie and George, who have formed a strong romantic connection on the show, opted for a more sensual performance.
But the other two pairs, who are purely platonic, took a more lighthearted approach to their routines.
The couples then got together to brainstorm their final pitches to win over the eliminated contestants and secure their vote.
Josie and George’s speech focused on their romantic connection, while Lachlan and Kiera’s pitch centred around the lifelong friendship they had formed.
Eliza and Alexander admitted they struggled to click with each other early on in the show, but said a natural friendship connection started to form by the third elimination challenge.
The pair spoke about how close they have become despite “being from two completely different worlds”.
Kiera and Lachlan showed their vulnerability during their pitch, with the 32-year-old racing car fanatic admitting he came on the show to find his "sense of self worth".
"Now I know what it feels like to be treated properly and be treated like I deserve," Lachlan confessed.
The eliminated couples then took turns chatting to host Sophie Monk in a private booth where they cast their final decision.
With an "overwhelming majority" of votes, Lachlan and Kiera were crowned the winners.
"You deserve this so much!" Lachlan said to Kiera during an emotional embrace.
"It means everything," a tearful Kiera gushed while the remaining two pairs congratulated them.
"I don’t even remember who I was when I first began. She seems like such a far distant memory from who I am today.”
Lachlan was equally emotional and said the show has been invaluable for building his confidence.
"I walk away from this experience with the best most positive headspace I've ever been in," he said.