The Ultimate Fighting Championship began its events in 2012 with UFC 142 on January 14. The year saw the successful UFC Featherweight title defense by José Aldo at UFC 142, the crowning of Carlos Condit at UFC 143 as the Interim Welterweight Champion, a new Lightweight Champion in Ben Henderson at UFC 144, a tournament to crown the first UFC Flyweight Champion at UFC on FX: Alves vs. Kampmann as well as the finales of The Ultimate Fighter 15 and The Ultimate Fighter: Brazil.

UFC 142: Aldo vs Mendes was held on January 14, 2012 in Rio de Janeiro, Brazil.

The event featured José Aldo defending his UFC Featherweight Championship against Chad Mendes. Aldo became WEC Featherweight Champion on November 18, 2009, which was later converted to a UFC Championship, and has defended his title four previous times with stoppages. Five of the last six fights, all wins, for Mendes resulted in unanimous decisions. Aldo defeated Mendes by knock out in 4:59 of the first round with a knee.

The co-main event was a bout between Vitor Belfort and Anthony Johnson. The day prior, during weigh-ins, Johnson failed to make the 185 pounds (84 kg) weight limit for the match and was 11 pounds (5.0 kg) over weight. Belfort agreed to fight Johnson in a catch weight bout of 197 pounds (89 kg) if Johnson did not weigh more than 205 pounds (93 kg) on fight day. Belfort was able to submit Johnson with a rear-naked choke in 4:49 of the first round. Johnson was cut by the UFC following the fight.

The Ultimate Fighting Championship (UFC) is the largest Mixed Martial Arts promotion company in the world, which hosts most of the top-ranked fighters in the sport and produces events worldwide. Based in the United States, the UFC has eight weight divisions and enforces the Unified Rules of Mixed Martial Arts.Dana White serves as the president of the UFC while Frank and Lorenzo Fertitta control the UFC's parent company, Zuffa, LLC.

The first UFC event was held in 1993 in Denver, Colorado. The purpose of the event was to identify the most effective martial art in a real fight between competitors of different fighting disciplines, including Boxing, Brazilian Jiu-Jitsu, Tae Kwon Do, Wrestling, Muay Thai, Karate and other styles. In subsequent competitions, fighters ventured outside their base style to utilize effective techniques from other disciplines, which indirectly helped create an entirely separate style of fighting known as present-day mixed martial arts.

With a cable-television deal and expansion into Canada, Europe, Australia the Middle East,Asia and new markets within the United States, the UFC as of 2011^[update] has gained in popularity, along with greater mainstream-media coverage. As of 2001^[update] viewers can access UFC programming on pay-per-view television in the U.S., Brazil, Australia, Canada, New Zealand and Italy. UFC programming can also be found on FX, Fuel TV, and Fox in the U.S., on ESPN in the United Kingdom and Ireland, as well as in 150 countries and 22 different languages worldwide. UFC also carries a mobile site for on-the-go users and a Sports Bars page for fans to find places showing the pay-per-view. It is also available on the Roku streaming player.

Year 143 (CXLIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Torquatus and Hipparchus (or, less frequently, year 896 Ab urbe condita). The denomination 143 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Nicholas Robert Diaz (born August 2, 1983) is a American mixed martial artist of Mexican descent. He is the former Strikeforce Welterweight Champion, WEC and IFC Welterweight Champion. He has competed in the Ultimate Fighting Championship, Pride Fighting Championships and Elite Xtreme Combat. Diaz was promoted to black belt in Brazilian Jiu-Jitsu by Cesar Gracie on May 8, 2007. Diaz trains at the Diaz brother's Cesar Gracie Jiu-Jitsu Academy in Lodi, California. Diaz holds the distinction of having never been submitted, and has been finished by strikes only once in 35 fights. He is currently ranked the #4 welterweight in the world by Sherdog, ESPN, MMAWeekly, and USA Today.

Diaz was born in Stockton , California. He is the older brother of UFC fighter Nate Diaz. He went to Tokay High School in Lodi for one year before dropping out. While a freshman, he was a member of the swimming team. Diaz has stated in the past that he is thankful his mother got him into swimming classes because swimming is one of the main reasons why his cardio is so impressive during his fights. Diaz has also said on multiple occasions that he had a hard childhood and grew up without his biological father.

Carlos Joseph Condit (born April 26, 1984) is an American mixed martial artist currently fighting for the Ultimate Fighting Championship where he is the interim welterweight champion. Condit initially received national attention for his run as the final WEC Welterweight Champion. He is known for his well rounded game, having a nearly equal amount of Submission and Knockout wins. Condit is also known for having an iron chin having never been knocked out in MMA competition. Condit is ranked as the #2 welterweight in the world Sherdog, #2 by ESPN and #1 by USA Today.Sherdog ranks him as the #10 pound-for-pound fighter in the world.

Condit attended CIbola High School on Albuquerque's West Side.

Condit formerly fought in the UFC's sister promotion, World Extreme Cagefighting (WEC), where he was the final WEC welterweight champion. He also competed for both Shootboxing and Pancrase in Japan.

Condit now trains at Jackson's Submission Fighting out of Albuquerque, NM.

Condit made his debut for the WEC at WEC 25 where he defeated Kyle Jensen in the first round via submission (Rear Naked Choke). Condit's second fight would be for the vacant WEC Welterweight Championship against John Alessio at WEC 26. Condit would win this fight in the second round, once again, by Rear Naked Choke and became the WEC Welterweight Champion.