UFC middleweight champion Anderson Silva has agreed to move up a weight class to face veteran light heavyweight Stephan Bonnar on short notice. The fight will headline UFC 153 on Oct. 13, in Rio de Janeiro.
UFC confirmed the fight on its website on Wednesday night. The main event was first reported by USA Today.
Silva accepted the bout after fellow Brazilian and featherweight champion Jose Aldo was forced out of the event and his highly anticipated bout against Frankie Edgar because of a foot injury. Edgar eventually was pulled from the card entirely.
Despite a three-fight win streak, Bonnar (14-7) had spoken about the possibility of retirement earlier this year. The 35-year-old has enjoyed a seven-year run with the UFC that began with a historic fight against Forrest Griffin on the finale of the first season of "The Ultimate Fighter" reality series.
Silva (32-4) hasn't fought at 205 pounds since posting a first-round knockout of Griffin in August 2009. After a win against Chael Sonnen in July, Silva had expressed a desire to sit out the rest of 2012 before accepting the fight.
Additionally, Brazilian light heavyweight Fabio Maldonado (18-5) will face rising prospect Glover Teixeira (18-2), who was left without an opponent earlier this week when former UFC champion Quinton Jackson bowed out because of an elbow injury.
UFC 153 will take place at HSBC Arena and now features a six-fight main card.