Dutchwoman Sanne Wevers caused a huge upset when she ruined Simone Biles' chances of scooping a record five golds at a single Olympics by winning the balance beam title in Rio on Monday.

The American had been expected to add the beam title to her team, all around and vault triumphs but drew gasps as she lost her footing following a front somersault and had to grab the beam with both hands to save herself from falling off.

Her score of 14.733 was only good enough for bronze behind team mate Laurie Hernandez.

Biles' misfortune allowed Wevers to become the first female Dutch gymnast to grab gold in an individual final, with a graceful routine featuring numerous spins, including a triple. She scored 15.466.

The Netherlands' only previous top prize for the women had been in the team competition in 1928.

Biles, a double world champion on the beam, was rock solid as she spun around 900 degrees on her right toes. There was not a wobble in sight as she executed her backflip into two layouts.

With the gold medal in her sights, she soared high into a front somersault but then it all went horribly wrong as her right foot missed its target on the beam and a routine that had been spellbinding till that moment lost its sparkle.

After completing her dismount, her frustration was clear for all to see as the megawatt smile that had lit up the Rio Olympic Arena time and again over the past week failed to materialise.

The judges pondered over her score for several minutes and when it was confirmed, Biles rolled her eyes skywards as the mark was almost a point lower than her qualifying effort of 15.633.

With five more competitors to go, Biles knew her chances of hanging on to lead with such a modest score were slim, and she was right.

Wevers mounted on the four-inch wide wood never having won a gold medal at an international meet but that shortcoming did not stop her from impressing the judges as she avoided any glaring errors to bag the top prize.

Biles will be back on Tuesday when she will be favourite to win the floor exercise.