Shaquille O'Neal proved his size is no match for furniture ... 'cause the Big Aristotle broke his chair while giving relationship advice to women, and the viral moment was caught on video!!

The hilarious mishap happened on an episode of Shaq's "The Big Podcast" -- when O'Neal and his co-host, Nischelle Turner, were talking about what leads people to ghost each other ... when disaster struck!

Shaq offered his response ... leaning back and stretching then suddenly, you hear a crack and a look of concern on the face of the gentle giant.

"I broke the chair, I broke the damn chair," O'Neal said to Turner, who was in awe at what she just witnessed.

50-year-old Shaq -- who stands over 7 feet tall and weighs over 300 pounds -- laughed about the blunder. However, O'Neal knew the jokes would fly once the Internet saw the footage.

O'Neal admittedly struggled with his weight during the pandemic ... but the big fella has been making strides to get back on the right track, including exploring options like going vegan.