Submission Underground 27 took place Sunday, October 10, 2021 with 10 fights in Portland, Oregon.

Mason Fowler will be defending his belt for the third time against Bellator heavyweight champion and former light heavyweight champion Ryan Bader. A former NCAA wrestling standout, Bader presents a different challenge than previous defenses. Also on the card, Craig Jones will face Vinny Magalhaes, who are both decorated Brazilian Jiu-Jitsu practitioners, along with former judo Olympic gold medalist Satoshi Ishii. Fowler won all of his previous defenses in the overtime ruleset.

Submission Underground 16 took place Sunday, July 12, 2020 with 10 fights in Portland, Oregon.

Submission Underground 10 took place Sunday, December 22, 2019 with 8 fights at Roseland Theater in Portland, Oregon.

Submission Underground 11 took place Sunday, February 23, 2020 with 3 fights at Roseland Theater in Portland, Oregon.

Submission Underground 8 took place Sunday, May 12, 2019 with 6 fights at Roseland Theater in Portland, Oregon.

Submission Underground 9 took place Sunday, July 7, 2019 with 6 fights at Roseland Theater in Portland, Oregon.