Mick Martin and Marsha Porter, authors of A DVD & Video Guide - 2005, found the biopic "...perfectly portraying the spirit of the heavyweight.

The events and characters are compelling and engaging..."[8] A review in Variety, only praised some aspects of the film including the acting and cinematography: "...the execution also works... Winkler utilizes the flashbacks sensibly, laying the groundwork for Marciano’s bizarre behavior after his career ended.

Tech credits are topnotch, highlighted by Clayton Halsey’s precise editing and Paul Sarossy’s smooth lensing.

"[9]—Michael Speier, VarietyA review in TV guide was less praiseworthy, stating, "Favreau lands this production’s sole knockout punch: He captures both the undefeated heavyweight champ's outward bravado and inner insecurity.

"[10] Richard Sandomir, writing for The New York Times, criticized extensively the film's lack of accuracy, judging it is a "docudrama that only occasionally lets truth stand in the way of the story.