Nigerian-born Israel Adesanya has lost his championship match to Jan Blachowicz of New Zealand.
The match was crucial to Adesanya, who was bidding to become the fifth fighter to hold two UFC titles.
Ahead of the match, Adesanya had said he was not bothered by Blachowiz being more experienced and older.
In the first two rounds, both men charged at each other and made minimal mistakes.
Adesanya made his jabs felt in the third round while Blachowicz failed to take him down despite several attempts on the middleweight champion.
Blachowicz managed to land a good left hook and charged forward with a series of punches before scoring a takedown.
But Adesanya struggled in the last two rounds as Blachowicz dominated the fight and the Nigerian fighter was eventually beaten for the first time in mixed martial arts.
The judges unanimously handed a resounding win to Blachowiz, with the scores 49-46, 49-45, 49-45.