Big meets small: Basketball legend Shaquille O'Neal dwarfs gymnast Simone Biles in viral Super Bowl photo

Standing at a mammoth 2.16m, retired basketball star Shaquille O'Neal made even his fellow National Basketball Association (NBA) players look tiny.

But it was a meeting of true David versus Goliath proportions when the 44-year-old, a four-time NBA champion, crossed paths with American gymnast Simone Biles.

Biles, 19, who won four gold medals at last year's Rio Olympics, uploaded a photo of the pair standing side-by-side on her social media accounts on Sunday night (Feb 5, US time).

"Hey shaq," read the caption from the petite 1.42m Biles.

Instagram and Twitter naturally exploded, with Biles' Instagram post garnering close to 300,000 likes in four hours.

Many noted that Biles still looked tiny and was dwarfed by O'Neal despite sporting a pair of heels.

The New England Patriots and Atlanta Falcons are vying for this year's Super Bowl, with the Patriots aiming to clinch a fifth title.

More than 100 million households across the US, and millions more across the world, are expected to tune in to the biggest sporting event in America.