The most savage elbow KO in UFC history?

UFC welterweight Matt Brown has won his first fight since 2015 with a brutal elbow to the head of Diego Sanchez at UFC Fight Night 120.

Incredibly, it could be the last fight for the 36-year-old Brown following speculation of an impending retirement announcement.

He had lost fights at three pay-per-view events in 2016, the last of which came just over 11 months ago at UFC 206 in December.

But during a tough first round against Sanchez, a 35-year-old who was fighting at welterweight for the first time since 2010, he landed the knockout blow.

Brown caught Sanchez's leg in a kick attempt, pushed him into the cage, held his head up with his left hand and then loaded up with a savage right elbow.

Sanchez collapsed to the canvas in a heap before appearing to regain consciousness almost immediately.

Brown celebrated with his two boys inside the cage in what was a strong hint towards his retirement.

Sanchez shared an Instagram post after the fight to confirm he would keep fighting, and he even had some nice praise for his conquerer.

"I love y'all, fans. Hope you guys liked the fight," he wrote.

"What can I say but it hurts to let down the family. But that's the fight game. I still have fight in me I'm not done yet I know that.

"(Matt Brown), what a classy competitor."