In his next fight at UFC 73 on July 7, 2007, Silva successfully defended his title against Nate Marquardt , winning by TKO at 4:50 in the first round. Three months later, on October 20, 2007, at UFC 77 , Silva fought a title defense rematch against Rich Franklin, in Franklin's hometown of Cincinnati , Ohio, at the . Bank Arena .  Silva defended his belt by defeating Franklin via TKO in the 2nd round. On March 1, 2008, at UFC 82 Silva fought Pride Middleweight champion Dan Henderson , in a title unification bout (UFC and Pride titles on the line). Henderson was believed to have the edge on the ground, having competed in the 1992 and 1996 Summer Olympics in Greco-Roman wrestling . Silva defended his title by defeating Henderson via rear naked choke in the 2nd round. At UFC Fight Night: Silva vs. Irvin on July 19, 2008, Silva made his debut at Light Heavyweight (205 lb (93 kg)) in a bout against James Irvin . Silva won via KO due to strikes in 1:01 of the first round after catching Irvin's attempted leg kick with his left arm and delivering a straight right that dropped Irvin to the mat, Silva then finished a prone Irvin with a blitz of punches to the head.     Irvin later tested positive for methadone and oxymorphone. 
On August 13, after several reschedules, the disciplinary hearing was held to decide on the subject. Silva's defense argued that a tainted sexual enhancement supplement was the root of the two failed tests for drostanolone and also appealed to mistakes in the NSAC testing procedures, pointing to a pair of drug tests, one on Jan. 19 and one after the fight, which Silva passed. He admitted to using both benzodiazepines the night prior to the fight as therapy to control stress and help him sleep. Silva's team was unable to explain the presence of androsterone in the Jan. 9 test. The commission rejected the defense and suspended him for one year retroactive to the date of the fight, as the current guidelines were not in effect at the time of the failed tests. He was also fined his full win bonus, as well as 30% of his show money, totaling $380,000. His victory was overturned to a no contest.  Diaz's hearing was delayed until September.  On September 14, Diaz was suspended for five years and also fined 33% of his show purse totaling $165,000.  Following his appeal four months later in January 2016, the suspension and fine were reduced to 18 months and $100,000 respectively. 
Another huge blow to the UFC today, as it was revealed that both UFC 183 headliners Anderson Silva and Nick Diaz failed drug tests ahead of their bout. Kevin Iole of Yahoo broke the story Tuesday evening. Diaz unsurprisingly tested positive over the limits for marijuana, but the more troubling test was that of Silva testing positive for drostanolone metabolites, in addition to androsterone. Drosotanolone is an anabolic steroid, often used during cutting cycles, whereas androsterone is a form of endogenous testosterone. Silva's Black House MMA teammates Kevin Casey and Brian Ortega both tested positive for drostanolone in 2014. Anderson Silva's failed test was a pre-fight test, Diaz's a post-fight test. As of now no punishment for either fighter has been announced. This comes weeks after UFC Light Heavyweight champion Jon Jones tested positive for cocaine. According to the Nevada State Athletic Commission, they are currently unaware of Silva failing any additional tests outside of the one administered January 9. The athletic commission claims they only got the tests back today, and hope to work to cut that time down to a week at most. The UFC released the following statement: On February 3, 2015, the UFC organization was notified by the Nevada State Athletic Commission that Anderson Silva tested positive for Drostanolone metabolites on his Jan. 9 out of competition drug test. UFC's understanding is that further testing will be conducted by the Commission to confirm these preliminary results. Anderson Silva has been an amazing champion and a true ambassador of the sport of mixed martial arts and the UFC, in Brazil as well as around the world. UFC is disappointed to learn of these initial results. The UFC has a strict, consistent policy against the use of any illegal and/or performance enhancing drugs, stimulants or masking agents by its athletes. Follow Sean Ross Sapp on Twitter at @SeanRossSapp . Got a news tip or correction? Send it to us by clicking here .