Question: Rocky Johnson is most notable for his win by submission over an American mixed martial artist who competes for who?
Context: Anthony "Mad Dog" Macias (born February 9, 1971) is an American mixed martial artist, who currently competes in the middleweight division.  Macias was introduced to MMA in a fight against Dan Severn at UFC 4, which Macias lost by submission.  His nickname, "Mad Dog", comes from his vicious style in the way he fights, reflected by the fact that only three of his 42 fights ended via decision. Tony Martin (born December 11, 1989) is an American mixed martial artist, who currently competes in the Lightweight division of the Ultimate Fighting Championship.  A professional competitor since 2012, eight out of Martin's twelve wins have come by way of submission. Mário Neto, known as Sukata (born 1974 in Brasília, Brazil) is a Brazilian mixed martial artist with a record of 12-5.  He is now in his 15th year as a mixed martial artist with a victory over UFC veterans Seth Petruzelli, Travis Fulton and Gary Goodridge.  Neto last defeated Dave Keeley by submission due to a guillotine choke at RFC - Recife Fighting Championship 5 in 2011. Demetrious Khrisna Johnson (born August 13, 1986) is an American mixed martial artist.  He is the first ever and the current Flyweight Champion of the Ultimate Fighting Championship (UFC).  He currently holds the longest active championship reign at ten title defenses.  He is also the #1 ranked pound for pound MMA fighter in the world.  Known for his quick striking and elusive movement, Johnson has also landed the most takedowns in UFC Flyweight history and holds the record for the latest finish in UFC history with a submission win at 4:59 of the fifth round against Kyoji Horiguchi.  He is also the only UFC fighter to record over 10 takedowns in three different fights. Wallid Farid Ismail (born February 23, 1968) is a Brazilian mixed martial artist and promoter.  Ismail holds a black belt in Brazilian jiu-jitsu (BJJ) under Carlson Gracie, and is an IVC mixed martial arts world champion and BJJ Champion.  In mixed martial arts, Ismail also competed for the UFC, and PRIDE, and most of wins in the sport came by way of submission. Benson Henderson (born November 16, 1983) is an American mixed martial artist who competes for Bellator MMA, and is a former UFC Lightweight Champion and WEC Lightweight Champion. Kyle James Bradley (born August 19, 1982) is an American mixed martial artist, who currently competes in the Welterweight division.  A professional mixed martial artist since 2003, Bradley is best known for his four fight stint with the Ultimate Fighting Championship.  He currently holds a record of 22–12 (1). Chris "The Westside Strangler" Brennan (born October 12, 1971) is an American mixed martial artist who competes in the Lightweight division.  He has competed for the UFC, PRIDE, King of the Cage and Shooto.  He is a former King of the Cage Middleweight Champion and former King of the Cage Middleweight Superfight Champion.  He is also one of 18 fighters to compete in the -77 kg division at the ADCC Submission Wrestling World Championships in 2005.  Chris was also the founder of Nogi Industries, a Mixed martial arts clothing company.  In 2014 Chris was inducted in to the Mixed Martial Arts Hall of Fame. Rocky Johnson (born July 24, 1971) is an American mixed martial artist.  He is most notable for his win by submission over future UFC Lightweight Champion Benson Henderson. Ricardo Arona (] ; born July 17, 1978) is a retired Brazilian mixed martial artist.  He has competed in PRIDE Fighting Championships and RINGS in his mixed martial arts career, and was a member of Brazilian Top Team.  He is the former RINGS Middleweight Champion, as well as the 2001 RINGS Middleweight Championship Tournament Winner, and 2005 PRIDE Middleweight Grand Prix Runner-Up.  In submission wrestling, he holds an undefeated record of 13-0, never losing a single point in a match, and is a three-time ADCC Champion.  He has notable wins in both MMA and submission grappling competition over Tito Ortiz, Jeff Monson, Renato Sobral, Vitor Belfort, Mark Kerr, Kazushi Sakuraba, Wanderlei Silva, Dan Henderson, Alistair Overeem, Murilo Rua, Jeremy Horn, Guy Mezger, and Dean Lister.
Answer: Bellator MMA