Question: John Raymond Kavanagh, an Irish martial arts coach, whose students include fighters such as Conor McGregor and Gunnar Nelson, an Icelandic mixed martial artist currently competing in the Welterweight division of what championship?

Context paragraphs:
Gunnar Nelson (fighter): Gunnar Lúðvík Nelson (born 28 July 1988) is an Icelandic mixed martial artist currently competing in the Welterweight division of the Ultimate Fighting Championship.  He is a black belt in Brazilian Jiu-Jitsu, which was awarded by Renzo Gracie after impressive results at the 2009 IBJJF Pan-Ams and the 2009 ADCC Submission Wrestling World Championship.  He is currently ranked #11 in the official UFC Welterweight rankings.  Gunnar is a teammate of fellow UFC fighter and Lightweight Champion Conor McGregor, and is a member of Mjölnir gym in Iceland, and SBG Ireland.

Tim Means: Timothy Carl "Tim" Means (born February 20, 1984) is an American professional mixed martial artist currently competing in the Welterweight division of the Ultimate Fighting Championship.  A professional competitor since 2004, Means has also formerly competed for King of the Cage and Legacy FC.  Means is the former King of the Cage Lightweight Champion and the former King of the Cage Junior Welterweight Champion.

Marius Žaromskis: Marius Žaromskis (born July 30, 1980) is a Lithuanian professional mixed martial artist currently competing in Bellator's Welterweight division.  A professional competitor since 2000, Zaromskis has formerly competed for Strikeforce, Cage Rage, DREAM, and also fought at Dynamite!!  2010.  Žaromskis won the DREAM 2009 Welterweight Grand Prix and became their inaugural Welterweight Champion.

Conor McGregor: Conor Anthony McGregor (Irish: "Conchúr Antóin Mac Gréagóir" ; born 14 July 1988) is an Irish professional mixed martial artist and professional boxer who is currently signed to the Ultimate Fighting Championship (UFC).  He is the reigning UFC Lightweight Champion, and former UFC Featherweight Champion.  During his mixed martial arts (MMA) career, McGregor has competed as a featherweight, lightweight, and welterweight.  As of 2017, McGregor is ranked 2nd on UFC's pound for pound rankings.

John Kavanagh (martial artist): John Raymond Kavanagh (born January 18, 1977) is an Irish martial arts coach, brazilian jiu-jitsu practitioner and former professional mixed martial artist.  His students include fighters such as Conor McGregor and Gunnar Nelson.

Ilima-Lei Macfarlane: Ilima-Lei Macfarlane (born 1990, in Honolulu, Hawaii) is an American professional mixed martial artist currently competing in the Flyweight division of the Bellator Fighting Championship.  Her first professional fight was an unsanctioned match, footage of which went viral and caused the California State Athletic Commission (CSAC) to launch an investigation into unsanctioned events.  They deemed the match a serious health hazard due to the skill level disparity between fighters (also known as a tomato can match-up).  The fight was discussed in an article on the popular Mixed Martial Arts news website, MMAjunkie.com.  The article described the video which, "features Macfarlane making her pro debut with the controversial Xplode Fight Series organization.  In it, Macfarlane takes on – and needs just 10 seconds to defeat – Katie Castro, who’s now 0-4 and clearly has no business being in a cage with an actual MMA fighter."

Dominique Steele: Dominique Steele (born January 25, 1988) is an American professional mixed martial artist currently competing in the Welterweight division of the Ultimate Fighting Championship.  A professional competitor since 2011, he has also competed for Strikeforce, Bellator, the Xtreme Fighting Championships, and CES MMA, where he was the Welterweight Champion.

Floyd Mayweather Jr. vs. Conor McGregor: Floyd Mayweather Jr. vs. Conor McGregor, also known as "The Money Fight" and "The Biggest Fight in Combat Sports History", was a professional boxing match between undefeated eleven-time five-division boxing world champion Floyd Mayweather Jr. and two-division mixed martial arts (MMA) world champion and at-the-time current UFC Lightweight Champion Conor McGregor.  The match took place at the T-Mobile Arena in Paradise, Nevada, on August 26, 2017 at the light-middleweight weight class (154 lbs; 69.9 kgs).  It was scheduled for twelve rounds.

Straight Blast Gym - Ireland: Straight Blast Gym Ireland is a mixed martial arts academy and professional team based in Dublin, Ireland.  It is run by John Kavanagh, and is part of Straight Blast Gym International.  The team has produced several Ultimate Fighting Championship (UFC) fighters, including UFC Lightweight champion Conor McGregor.

Rory MacDonald (fighter): Rory Joseph MacDonald (born July 22, 1989) is a Canadian mixed martial artist currently competing in the Welterweight division of Bellator MMA.  MacDonald is considered one of the most well rounded MMA fighters in the world, and having been a professional competitor since 2005, he is a former UFC top contender who obtained an overall record of (9-4) with the promotion, and also a former King of the Cage Lightweight Champion.

Supporting paragraphs: John Kavanagh (martial artist) Gunnar Nelson (fighter)
Answer: the Ultimate Fighting Championship