And, well, "The Young Assassin" was involved in some fireworks, but he was on the wrong end of them at Houston's Toyota Center on Friday night.
Short-notice replacement Derek Campos got the best of the veteran slugger, finishing him via TKO at the 32-second mark of the second round.
Guillard (32-16-2), who missed weight on his first attempt Thursday before making it the second time, came out firing from the outset. But Campos took him down and kept him there for the bulk of the stanza.
In the second, Campos didn't waste any time, opening up with a flurry of lefts and rights, swarming Guillard and dropping him to the canvas before the bout was waved off.