UFC 331 results, highlights: Sean Sharaf scores all-time upset in vicious knockout of Gable Steveson

At UFC 331, underdog Sean Sharaf secured a monumental and historic upset by knocking out Gable Steveson in just 12 seconds.

Sharaf achieved the victory by landing a picture-perfect left hook that left Steveson out cold.

The swift finish is being regarded by analysts as one of the biggest and most vicious upsets in the history of the Ultimate Fighting Championship.