Jimi Manuwa began training in mixed martial arts in 2007 following a weight lifting injury where ruptured a chest muscle while bench pressing 185 kg (407+ lbs). He currently trains at Keddles Gym with Alan Keddle and Dino Miringou and at Nova Forca BJJ with Ricardo Da Silva.
As of December 2011, Jimi Manuwa is undefeated, going 11 wins and 0 losses. He has been fighting for the Cage Rage UK name since his third fight, becoming the promotion's champion in his third fight under them. He has successfully defended his title 5 times, more than any other champion in the company, past or present.
Manuwa famously turned down a contract offer from the Ultimate Fighting Championship, feeling it wasn't the right time in his career to accept it. He did state that reaching the UFC was his "ultimate goal" in the future. He was then offered to fight at the UFC 138 event, but also refused that one, citing that he hasn't competed since summer of 2010, and that "If he fought on the October card that would have been after a fifteen month layoff, which is not ideal under any circumstances. You do need to be fighting regularly to stay sharp..."
He successfully defend his title for the 5th time at UCMMA 24 - Hands of War against Nick Chapman.
After defending his title a record 5th time, Manuwa signed a four-fight exclusive contract with BAMMA. He made his debut at BAMMA 8. He faced Frenchman Anthony Rea and won the fight via TKO.