Murilo "Ninja" Rua has retired from MMA as an active competitor. Following a third round knockout loss earlier today (May 21, 2011) to Tom "Kong" Watson at BAMMA 6, Rua took to Twitter to announce his leaving the sport as an active competitor: "I would like to announce officially my retirement from PRO MMA fights tonight. It was an amazing run, and its a very tough moment ... But there comes a time for all in life, and it's time to move on. I am proud of all I did in MMA and all experiences I had ... I will continue to work with MMA, doing seminars, teaching classes, training fighters, and doing my share to help our sport that I love so much."