In his professional mixed martial arts debut at SuperBrawl, Fukuda surprised many by taking Joe Doerksen to decision.
At DEEP 49, Riki successfully defended the title against Ryuta Sakurai winning the fight via TKO due to knees.
In the first round, Fukuda successfully completed a takedown, but in the process Sakurai fell out of the ring and hit his face on the bell.
Despite the loss on the scorecards, UFC president Dana White felt Fukuda won the bout and stated on his Twitter account that both fighters would be paid a win bonus.
[5] However, Fukuda was forced out of the bout due to a knee injury sustained in a car accident[6] and replaced by Costas Philippou.
[11] Fukuda was subsequently released from the organization after testing positive for banned substances during his post fight drug screening.
[12] It was later revealed to be linked to over the counter cold medicine Fukuda had taken when he fell ill during his process of making weight for the bout.
[13] Fukuda faced Hee Seung Kim in his debut bout at Road FC: Korea 1 on January 18, 2014.