Embattled Ultimate Fighting Championship (UFC) Welterweight slugger Nick Diaz, who's riding the pine while his lawyer hashes it out with the Nevada State Athletic Commission (NSAC) following his failed drug test in the wake of UFC 143 back in February, will participate in the upcoming World Jiu-Jitsu Expo (WJJE) on May 12, 2012, in Long Beach, California.

And he's going straight to the top.

Diaz, himself a Brazilian jiu-jitsu black belt under Cesar Gracie, has been paired off in a "superfight" against Abu Dhabi Combat Club (ADCC) Champion and all-around grappling badass Braulio Estima, according to a report from MMAFighting.com.

The 31-year-old Estima has won a plethora of BJJ competitions over the past decade. He most recently defeated Ronaldo "Jacare" Souza in a super-fight at the 2011 edition of the prestigious Abu Dhabi Combat Club Submission Wrestling Championship and won gold medals at the 2009 ADCC tournament in the 88kg and Absolute divisions. He is currently training with the Blackzilians in South Florida in preparation for his MMA debut later this year.

Credit to Diaz for not participating in a grappling tournament just to squash some up-and-comer, but even this seems like a bit of a mismatch, considering Diaz hasn't rolled in any sort of competition in over two years.

But I'm not sure he'd want it any other way.

Grappling highlights from each competitor after the jump.

Nick Diaz

Braulio Estima

For all the info you need to know on the World Jiu-Jitsu Expo, which will also include free seminars with top jiu-jitsu experts Renzo Gracie, Roger Gracie, Robert Drysdale, Rodrigo Comprido and Andre Galvao, among others, click here.