One of the all-time great careers in MMA history came to a close Friday when Demetrious Johnson announced his retirement from the sport.

The former longtime UFC flyweight champion and ONE Championship titleholder Johnson (25-4-1) made a special entrance to the cage at ONE Championship 168 at Ball Arena in Denver and told the crowd he was done fighting in MMA.

It was an emotional speech from "Mighty Mouse," who moments later became the first fighter to be inducted into the ONE Championship Hall of Fame. Johnson didn't rule out a future return in grappling competitions, but he said there is no longer a future in the combat sport where he made all his fame.

Reactions to Johnson's announcement poured in over social media, and you can check out the overwhelming praise for his legendary run below.

MMA Junkie Mike Bohn MMA Junkie Terrance McKinney Ben Fowlkes Yves Edwards Ariel Helwani Takeya Mizugaki Jed I Goodman Jeremy Kennedy Rich Chou MMA Junkie Michael Bisping Ben Davis ONE Championship ONE Championship Derek Brunson ONE Championship Demetrious Johnson