The promotion are into the semi-final of their €1million (£850,000) “Gamechanger” welterweight tournament.
Their win-or-go-home format kicked off with 16 contenders but now just four remain.
Frankfurt, Germany hosts the September 16 semis with ex-welterweight Champion David Kozma taking on Bojan Velickovic while Louis Glismann faces Andreas Michailidis.
Each fighter is guaranteed to make £68,000 (€80k) in the semis with finalists taking home at least £110k (€130k) of the €1m prize pot.
Pavol Neruda, co-owner of OKTAGON MMA, said: “We want to reward our fighters with the pay that they deserve.
“The €1million euro prize pot for the Gamechanger has given the 16 competing fighters the chance to earn money, as well as make history by winning the tournament.
“We want to create heroes with this tournament, but our fighters’ health is the most important thing, and financial rewards are important.
“As we have grown, the prize money has increased, and will continue to do so.”
OKTAGON also celebrated a broadcast deal which will see the promotion streamed on Channel 4 and their YouTube channel.
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The first show will be aired on November 4 in Manchester, as X Factor star Jake Quickenden makes his MMA debut.
Quickenden’s journey from “Stage to the Cage” will also be documented in a series available on Channel 4.