Nick Diaz UFC 137 weigh-inMake that semi-retired.

Welterweight mixed martial artist Nick Diaz will be taking on world class Brazilian jiu-jitsu player Braulio Estima in a BJJ superfight next month in California. The surly Stocktonian has not competed in a strictly BJJ match in two years.

A BJJ black belt under Cesar Gracie, Diaz hangs his hat on top-notch grappling skills, but he’ll have his hands full with Estima. The 31-year-old Brazilian is as decorated a grappler as they come, having won multiple BJJ competitions at the highest level. A two-division Abu Dhabi Combat Club Submission Wrestling World Championship winner in 2009, Estima will take on Diaz as he prepares to transition from high level grappling to mixed martial arts competition later this year.

Most recently, Estima took out former Strikeforce middleweight champ Ronaldo “Jacare” Souza in a super-fight at the 2011 ADCC tournament.

Diaz, who has never been submitted in BJJ competition, announced his retirement from MMA following a controversial unanimous decision loss to Carlos Condit at UFC 143 earlier this year. That loss cost him a shot at UFC welterweight champ Georges St-Pierre and also ended an eleven-fight winning streak that included victories over BJ Penn, Paul Daley, KJ Noons, and Frank Shamrock.

The Diaz-Estima match will be fought no-gi at 180lbs and is slated to take place on May 12 in Long Beach, California as part of the World Jiu-Jitsu Expo.