In the opening round of the tournament, Yoshida defeated two-time interim Pancrase champion Katsuya Inoue by knockout.
He went on to defeat Matt Cain in the quarterfinals and former Shooto champion Akira Kikuchi in the semi-finals of the tournament.
In the finals, Yoshida defeated Dan Hardy by disqualification after being struck by a kick to the groin, becoming the first Cage Force welterweight tournament winner.
It was originally speculated that the winners of the Cage Force tournaments were to be selected to compete in the UFC's active roster.
UFC reported, "Yoshida, who remained on the canvas while being tended to by commission doctors, was removed from the Octagon on a stretcher as a precautionary measure.
Yoshida then fought Brandon Wolff at UFC 98: Evans vs. Machida on May 23, 2009, and won the bout by guillotine choke in the first round.
Yoshida was expected to face Nate Marquardt in the main event of BAMMA 9 to determine an Inaugural World Welterweight Champion.