Grant’s pinnacle of his boxing career came in 2000 when he unsuccessfully challenged Lennox Lewis for the IBF, WBC and IBO heavyweight titles.

In his early career, Grant beat Corey Sanders, Ross Puritty, Lionel Butler, Al Cole, Jorge Luis Gonzalez, David Izon and Obed Sullivan.

Grant's undefeated record and victories against Sullivan, Savarese and Golota earned him an opportunity to challenge newly crowned undisputed heavyweight champion Lennox Lewis.

He got back to his feet and was beaten badly by Lewis, a left hand on the side of the head sending Grant reeling into the corner and counting as a second knockdown.

Since the loss, Grant has fought sporadically against limited opposition while having several high-profile trainers, including Don Turner, Teddy Atlas,[3] Buddy McGirt and most recently Eddie Mustafa Muhammad.

On May 7, 2010, Grant fought for the first time in eighteen months and won by first-round technical knockout over Kevin Burnett at Oheka Castle, Huntingdon, NY.

[7] After an 18-month layoff, Grant defended the WBF belt against France-based Cameroonian Carlos Takam on May 24, 2013, in Noisy-le-Grand, France, losing by 8th-round technical knockout.