There was a boxing event in Philadelphia today, and with it, an upset.

Yes, Roy Jones Jr. did show up at a press conference in downtown Philly to sell his Dec. 4 WBU cruiserweight championship fight against Bobby Gunn at the Northeast Philadelphia Armory.

"He's a celebrity," Gunn said. "He is like the Michael Jordan of boxing."

Jones, 44, is 54-8 and hasn't fought since June of 2012. But he has won his last two fights and is making noises about a couple of notable boxers.

"Floyd Mayweather is talking about being the best of all-time, and he is starting to (tick) me off," Jones said. "And I still don't like Bernard Hopkins. So there are a lot of options for me out there."

Jones is 1-1 against Hopkins, the light-heavyweight champion ... and many rounds removed from that level. So Gunn (21-5), it will be, for 12 rounds, in a club-fight setting that frankly would seem to be beneath Jones, a former world heavyweight champion and once the best fighter, pound for pound, in the world.

"This fight will not be forgotten," Gunn said. "And the critics will eat their words."

Gunn, 39, last fought in 2012, breaking his hand and losing to James Toney.