LAS VEGAS -- Junior dos Santos weighed-in for his first UFC heavyweight title defense at 239 pounds on Friday.
He then predicted a short fight.
The Brazilian champion believes he'll knock out challenger Frank Mir in the second round on Saturday at UFC 146.
"I'm ready for this fight," dos Santos said. "If he's not ready, it's going to be fast. It's going to be a knockout, second round."
Mir (16-5), a former two-time heavyweight champion, weighed in heavier than dos Santos (14-1) at 261 pounds. The 32-year-old holds the record for most wins in the UFC heavyweight division with 14.
"Both of us are first-round fighters," Mir said. "I think it will be a fast and explosive fight."
UFC 146 marks the first time an entire five-fight main card consists of heavyweight fights. The promotion has taken to reminding its fans this week that more than one ton of professional fighters will appear in the Octagon this weekend.
On the undercard, former No. 1 welterweight contender Dan Hardy (23-10) looks to turn things around after losing four straight. He weighed 171 pounds.