Glover Teixeira and Jiri Prochazka went toe-to-toe for the best part of five rounds before Prochazka pulled off the stunning win with under thirty seconds to go.
Prochazka looked to have the upper hand on the 42-year-old in the second round when he wobbled him with multiple blows.
Teixeira however showed his guile by taking the fight to the canvas and ending the round with hellacious elbows that opened a nasty cut above the right eye.
The fight continued along a similar pattern in the third and fourth rounds as Prochazka landed brutal shots, opening up several cuts on the champs face only for the old champion to take the fight back to the canvas and assert his dominance.
Teixeira looked to have the fight wrapped up after rocking his opponent in the fifth round, but his over eagerness got the better of him as he attempted a submission.
The fight then went to the canvas and an exhausted Teixeira made the mistake of giving up his back and Prochazka pounced. Locking in a rear-naked choke and drawing a tap from the Brazilian to secure the light heavyweight title.
To rub salt into the wounds for Teixeira, the judges scorecards showed he was up on two of the three cards entering the final round. Hold on for another 28 seconds and he retains his belt.
Fans were split as the final bell rang out, with many undecided on how the scores were going to go. Nobody expected what they heard when Bruce Buffer read out the three cards.
Fans watching on believed Santos had done enough to pull off the historic upset, but it was one judges card having Shevchenko winning 49-46 that led to outrage.