Seemingly back on track, Barrett accepted the challenge of facing Wladimir Klitschko in London, England.  Not as prepared as he should have been, Barrett was knocked out for the first and only time in his career by the Ukrainian giant, surviving for seven rounds only because of his heart and courage. Boxing is a very unforgiving sport, and Barrett needed to prove his mettle immediately.

Barrett then faced Buffalo sensation “Baby” Joe Mesi at Madison Square Garden and on HBO on Dec. 6, 2003. Mesi is known for early-round knockouts before hometown crowds in Buffalo, and he started quickly against Barrett and knocked him down in round five with a thunderous right hand to the jaw.

Undaunted, Barrett survived Mesi’s best shots and managed to battle back in the second half of the contest. Mesi walked into a sharp left hook to the jaw at the start of the seventh round that landed flush, and Mesi dropped to one knee—the first knockdown of his career. Barrett punished Mesi throughout the remainder of the round, and with only 41 seconds left, Barrett jolted Mesi again with a solid left hook to the head. Both men traded shots in the center of the ring as the Garden fans stood and cheered the fireworks.

Despite a left eye that was almost closed and the fact Barrett had evened the knockdowns, Mesi won by majority decision. Judge Joseph Dwyer tallied 94-93, and Arthur Mercante Sr. scored it 95-93, both for Mesi, while Tom Schreck had it 94-94, a draw. The verdict was greeted with a chorus of boos by the Garden crowd, and many believe Barrett would have won the fight had it been scheduled for more than 10 rounds.

Barrett then took on undefeated and highly touted Dominick Guinn (24-0, 17 KOs) of Hot Springs, Ark., on March 27, 2004, in the co-main event on HBO’s Boxing After Dark. Barrett asserted his dominance from round one, throwing punishing hooks to the body and head. Barrett won a hard-fought split decision over the hometown favorite.

Barrett faced another undefeated heavyweight contender in Owen “What the Heck” Beck (24-0, 18 KOs) in an IBF and WBC elimination bout in St. Louis on Feb. 5. 2005. Both fighters came out strong in what became one of the best heavyweight fights of the year.

Barrett used his superior ring experience to thwart Beck’s spirited attacks. Barrett floored the Jamaican in the second round, but a game Beck fought back valiantly, lasting until the ninth round when Barrett decked him twice more before the referee halted the action.

Barrett was now the mandatory challenger to IBF heavyweight champion Chris Byrd and the No. 2-ranked contender in the WBC. Two Gunz could have simply waited for the world title shot he had earned against Byrd, but promoter Don King had other ideas.

Likewise, WBC No. 1-ranked mandatory challenger Hasim “The Rock” Rahman had been waiting through three postponements to face WBC champion Vitali Klitschko. Due to these delays, King successfully petitioned the WBC to sanction a match between Rahman and Barrett for the WBC interim championship. Both fighters were brave and accepted the challenge, knowing only one fighter would move ahead to a world championship match.

Rahman vs. Barrett took place at the United Center in Chicago on Aug. 13, 2005. In the year leading up to the fight, Barrett has undergone many personal and professional changes. His longtime mentor and friend Tommy Parks passed away. Harold “Shadow” Knight, who also trained world champion Lennox Louis was named his trainer. He also was experiencing personal problems at home that few new about. If all of this were not enough, Monte and Rock are close friends. Both assured everyone it would not affect their performance in the ring.

Rahman established his jab early, winning the first two rounds. Barrett dug in during the third round and ripped Rahman with a sharp left hand. Barrett seemed unaware that he had buzzed his opponent and did not apply any extra pressure before the bell sounded ending the round. That punch alone won Barrett the round on two of the three judges’ scorecards.

Monte fell silent after the third, abnormally content to allow Rahman to out-work him. He seemed to wake up in the last three rounds of the contest winning two of the last three rounds on two scorecards and winning the tenth on the other. Regardless, it was too late for Monte who lost by unanimous decision.

Rahman went from interim WBC champion to outright champion after Klitschko sustained an injury preparing for a meeting that never took place on Nov. 12, 2005.