In 2002, Yoshida turned fully his attention to the world of mixed martial arts, where he had already worked as a color commentator, and signed up with Pride Fighting Championship to become a fighter.
This ruleset had been proposed by Royce due to the 50th anniversary of the Masahiko Kimura vs. Hélio Gracie fight, and as such the bout was touted as another "judo vs. Brazilian jiu-jitsu" contest.
[10] Started the fight, Royce immediately pulled guard in order to avoid Yoshida's powerful nage-waza, frustrating his initial gameplan of entering the ground through a throw.
After the event, the Gracie family apologized but argued not only that Royce had not passed out, but also that the referee had not authority to stop the match anyway, and demanded the fight result to be changed to no contest.
At PRIDE Total Elimination 2003, Yoshida faced shoot-style ace Kiyoshi Tamura in the first round of the Middleweight Grand Prix Tournament.
[9] Royce, who fought this time without his gi top, caused controversy when he aimed three consecutive low blows on Yoshida, eventually scoring one that stopped the match for minutes.
Finally able to continue fighting, Yoshida knocked down Royce with a combination and attacked him on the ground, besieging his half guard and coming to capture his back once.
The Brazilian answered capitalizing on an armlock attempt to gain top position, ultimately taking back mount while hitting repeatedly the judoka with hammerfists.
[14] The second round saw an initial battle for an ankle lock, but it quickly returned to the last position, with Royce straddling a turtled down Yoshida and scoring strikes in the search of a submission.
In 2004, after promoters failed at getting a rubber match with Royce Gracie as Yoshida wished,[15] the judoka was left to face the similarly debuting Rulon Gardner.
Gardner, Olympic gold medalist in Greco-Roman wrestling and much heavier than Hidehiko, performed unexpectedly and dominated Yoshida with stand-up for a unanimous decision.
This time without their gis, Yoshida started the match throwing punches and taking Ogawa down, and then a long and aggressive exchange of reversions and ground and pound happened.
In a classic striker vs. grappler fashion, Yoshida attempted to throw Mirko to the mat, almost scoring a uchi mata off the corner in an instance, but the Croatian powered out of it and kept landing leg kicks.
Yoshida outboxed the much heavier British fighter and threatened him with several throw to armbar attempts, as well as some leglocks, but Thompson then featured a controversial moment for pushing Hidehiko between the ropes of the ring to the outside.
The bout would have yet another controversial moment, as the referee didn't stop the match, and allowed James to strike further a barely conscious Yoshida for a late stoppage.
[17] In March 2008, Yoshida made his debut in World Victory Road at its inaugural show Sengoku against catch wrestling specialist and former training partner Josh Barnett.
Come the third round, when Hidehiko dropped to his knees to avoid another suplex, Barnett gained top position and performed a heel hook, making Yoshida tap out.
It was a short affair, with Yoshida taking the fight to the ground, gaining a kesa-gatame position and performing a neck crank to submit the UFC champion.
The third round saw Yoshida stunning Kikuta with a punch and scoring a judo throw, but the Koga trainee took his back and kept striking on him for the rest of the match, eventually winning the decision.