UFC 183 featured two fighters, Anderson Silva and Nick Diaz, who managed to pull in strong numbers in both attendance and live gate receipts.

The pay-per-view event, held at the MGM Grand Garden Arena in Las Vegas, which featured the return of Anderson "The Spider" Silva against Nick Diaz, became one of the top ten events in the state's MMA history, reports MMA Junkie.

According to the report, UFC 183 pulled in an announced attendance of 13,114, which amounts to a live gate of $4.5 million. The achievement puts UFC 183 at No. 9 on Nevada's list of top MMA gates. The state records its top draws in terms of gate amount.

But in stunning turn of events, Kevin Iole for Cage Writer reported the two fighters in the main event failed their respective drug tests.

Silva, who is returning from a 13-month layoff after suffering a gruesome leg injury against UFC Middleweight champion Chris Weidman, tested positive for two anabolic steroids"”drostanolone, and androstane.

Diaz, for his part, was found to have elevated levels of marijuana metabolites in his system. It was the third time in Diaz's career that he has tested positive for marijuana.

Iole points out that what makes the news even more stunning is that Silva's test results came from an out of competition test conducted by the Nevada Athletic Commission back in January 9, but the Salt Lake City-based Sports Medicine and Research Laboratory (SMARTL) did not return the result to the commission until last Tuesday.

"I would have had no problem calling the fight once I had this result," said commission chairman Francisco Aguilar, who could not explain why he did not receive the test results sooner.

Dr. Daniel Eichner of SMARTL could not be reached for comment.

Drostanolone is an anabolic steroid commonly used by body builders to reduce fat. According to EliteFitness, it lowers water retention, cutting weight, and allowing for a more toned physique.

Silva won a unanimous decision over Diaz by scores of 50-45, 50-45, and 49-46 in the five-round fight.