Fans spot Simone Biles' reaction midway through performance after she made mistake before winning gold medal

Fans were quick to notice Simone Biles' facial expression midway through the floor exercise portion of her all-around gymnastics performance.

Biles has just helped lead Team USA to a gold medal at the Paris Olympics Games, the fourth in US history and the 27-year-old's eighth in in her Olympic career.

An athlete that truly transcends the sport of gymnastics and widely regarded as the best performer of all time, her performances are closely watched around the world, so it's no surprise that fans noticed this small detail in her routine.

Simone Biles helped herself to another Olympic gold medal. (Naomi Baker/Getty Images)

Biles was part of a stacked all-around gymnastics team, with the likes of Jordan Chiles, Hezly Rivera, Sunisa Lee and Jade Carey making up the rest of the all-star team.

The result makes Biles the single most decorated US Olympic gymnast, with five gold medals, one silver and two bronzes.

All five athletes showed up though, with stellar performances across all apparatuses to help the US take gold home yet again - though it wasn't without a small bit of drama.

One of the noteworthy moments that had fans at home holding their breath, was when Biles was performing her final routine of the night - the floor exercise.

All was going well as the star athlete flipped and leapt on the springboard floor, until something (almost) unthinkable happened.

The gymnast accidentally stepped out of bounds. (BBC)

Biles landed and lost balance for a second, accidentally stepping out of bounds and giving herself a .1 deduction, as per Olympic scoring rules.

In the grand scheme of things, not much considering the rest of the performance managed to help secure the gold medal, but it showed that Biles might be slightly - just slightly - human.

Fans took to social media, as screenshots of the athlete realising she'd made a tiny mistake did the rounds on X, as she cheekily stuck her tongue out before continuing with her routine.

However, not many seemed to care about the slip-up, as one fan thought it showed her humility: "Simone always makes me smile! I love her! Her heart is warm!"

Biles brushed it off and went on. (BBC)

A second fan celebrated: "THE MOST DECORATED OLYMPIC GYMNAST EVER PERIOD"

While another user said: "My favourite bit of the Simone Biles Netflix documentary was when she talked about how the support and encouragement of the other gymnasts was key to her comeback.

"Look at them now."

The whole team performed in front of a star-studded crowd, with the likes of Michael Phelps and Serena Williams also watching on in support.

Biles will compete in the Women's All-round gymnastics final on Thursday (1 July).

Team GB's current medal count - 12

Gold medallists

• Rosalind Canter, Laura Collett, Tom McEwen: Equestrian - Eventing team
• Tom Pidcock: Mountain Bike - Men's cross country
• Nathan Hales: Shooting - Men's trap
• Tom Dean, Kieran Bird, James Guy, Jack McMillan, Matthew Richards, Duncan Scott: Swimming - Men's 4x200m freestyle

Silver medallists

• Anna Henderson: Cycling - Women's individual time trial
• Adam Peaty: Swimming - Men's 100m breaststroke
• Tom Daley and Noah Williams: Diving - Men's synchronised 10m platform
• Adam Burgess: Canoe Slalom - Men's canoe single
• Matthew Richards: Swimming - Men's 200m freestyle

Bronze medallists

• Yasmin Harper and Scarlett Mew Jensen: Diving - Women's synchronised 3m springboard
• Kimberley Woods: Canoe - Women's slalom
• Laura Collett: Equestrian - Eventing individual