Marco Antônio de Lima Ruas (Portuguese pronunciation: [ˈmaʁku ˈʁuɐs]; born 23 January 1961) is a Brazilian former mixed martial arts fighter, submission wrestler, kickboxer and instructor.

Although he was billed as a representative of Luta Livre and thus a high-level submission grappler, he was an equally capable and skilled Muay Thai striker with experience in Capoeira, Boxing, and Taekwondo.

[13] He firstly faced Larry Cureton, who outweighed him by 40 lbs, but Ruas submitted him with a heel hook after a methodical grapple.

After a failed heel hook attempt, Ruas controlled Pardoel and attacked him with knees and punches on the ground, making him tap out.

Both fighters used a passive approach to the fight, with Ruas blocking Taktarov's takedown attempts and seizing all the opportunities to strike him, actually making him bleed profusely.

In 1996 he joined the nascent World Vale Tudo Championship (WVC) organized by his manager Frederico Lapenda, fighting in the superfight against UFC 3 Tournament Champion Steve Jennum in Tokyo, Japan.

He finished his run in the organization with his last superfight against UFC 2 finalist Patrick Smith in the WVC 4 event, easily winning with a heel hook.

Ruas briefly joined the stable of Antônio "Sebastião" Lacerda, a wealthy man from the north of Brazil and self-proclaimed "Master of Death" who appeared in Rio de Janeiro in 1996 claiming to have spent a long period of time in Japan learning "the deadly art of Yawara."

Despite his dubious credentials, Lacerda was able to recruit some established competitors into his sect, including Ruas and Edson Carvalho, a judo national team member and a Carlson Gracie black belt.

In a major upset, Otsuka fought with tenacity, taking Ruas down and performing ground-and-pound, defending a fully locked rear naked choke and forcing a TKO by medical stoppage in the second round.

[19] At this point semi-retired, in 2001 Ruas defeated Jason Lambert at Ultimate Pankration in California in less than 1 minute with a heel hook.

Marco Ruas was invited to participate in the newly formed MMA promotion International Fight League (IFL).

This promotion would be divided into different teams (later becoming simply MMA camps) instead of one-on-one affairs, and at the end one of the seasons one of the teams/camps was crowned champion.

Ruas accepted it but requested four months to train instead of fighting right away in the gym, Gracie denied it since he would leave Brazil to the United States before that.

[24] A few of Ruas's teammates also joined in and the discussion got heated up and Hélio said "Maybe we should make a list of people who want to fight Rickson", one of the fighters who accepted the challenge was Hugo Duarte, who would have his own scraps with Gracie.

Ruas made a cameo appearance as a jealous husband in Kickboxer 3, in which his character fought and lost to Sasha Mitchell's David Sloane at a party.