Many of the fans in the MGM Grand Garden Arena disagreed with the judges and booed the call.
Brown won the first round in dominant fashion, battering Nunes standing and on the ground. Nunes came out of the first round with a swollen eye.
But in the next two rounds Nunes stymied Brown on the feet and stuffed his take down attempts.The merciless logic of MMA judging means that Nunes edging out two extremely close rounds outweighs Brown beating him thoroughly in a single round.
Brown is 2-2 since losing his title to now UFC champ Jose Aldo in November 2009 at WEC 44. He submitted Anthony Morrison at WEC 46 only to be KO'd by Manny Gamburyan at WEC 48. He rebounded with a KO win over Cole Province at WEC 51.
Personal issues were said to have impacted Brown's performance during that time.
Brown once fought at lightweight for the promotion way back at UFC 47 in 2004 against Genki Sudo, losing by arm triangle submission to the Japanese star.
Nunes trains with Brazil's Team Nogueira. He is coming off back-to-back decision wins over Tyler Toner at WEC 51 and Rafael Assuncao at WEC 49. Prior to that he took his only WEC loss in a decision against L.C. Davis 44. All of his fights for the WEC went to decision.