Seven duelers took part in Diamond Quest XXXI, including: Matt Simon (two time DQ winner), Ria Graziano (winner of DQ XXX), Harris d'Artainian, Stick, Face Loran (winner of XXIII), Anubis Karos, and Tim Enralyte.

Fought in a round-robin style, both Harris and Matt ended the tourney with a record of 5-1 and so fought again to determine the winner of the tourney. (Final records for the regular part of the tourney were: Matt 5-1, Harris 5-1, Stick 4-2, Face 3-3, Anubis 1-5, Tim 1-5)

Ria Graziano stepped out of her fighting togs and into the role of referee for the final face-off between Matt and Harris. The match got off to a quick start and came to a quick finish in the 7th round when Matt swept down Harris to win 5-2.

Matt's win also gives him the distinction of being the first three time winner of a Diamond Quest.