IBF featherweight champion Tom Johnson at London Arena. He dominated the fight, retaining his IBO Inter-Continental Featherweight Title on his way to a unanimous decision, 117–113, 119–111, 119–109, on the judges' cards. Harrison rounded the year off with the first defence of his Commonwealth title. He stopped Eric Odumase by TKO in round 12 of the contest at Waterfront Hall in Belfast. In March 2001, Harrison added the vacant British title to his Commonwealth Featherweight title with a win against Liverpool's Richie Wenton at Ponds Forge in Sheffield. Harrison put Wenton down in the first round but it wasn't until the fourth round referee Dave Parris stopped the fight after continued pressure from Harrison. After the fight Harrison said "It was my sweetest win". Harrison made the first defence of his British title six months later against former title holder Gary Thornhill at the M.E.N. Arena in Manchester. Harrison dropped his opponent with a left hook to the body and the contest was halted after 31 seconds of round five. Harrison made the final defence of his British title in November 2001 against former WBO featherweight champion Steve Robinson. Harrison was in control for the duration of the fight with referee Richie Davies stopping the fight only nine seconds of the round three remaining. At the end of 2001, Harrison was voted Young Boxer of the Year by the Professional Boxing Association and the Boxing Writers' Club. World Champion Harrison became WBO featherweight champion in 2002, defeating former Olympic bronze medalist Julio Pablo Chacon with a unanimous points decision at Breahead Arena in Glasgow by scores of 117–111, 117-112 and 117–111. With Harrison's win, he became Scotland's eight world champion. After picking up the world title for the first time Harrison ended the year, The Ring's #8-ranked featherweight in the world. Harrison made his first world title defense against Wayne McCullough in March 2003 at Braehead Arena. Harrison comprehensively outpointed McCullough winning on the judges' scorecards 119–109, 119-108 and 120–108. After the fight McCullough said Harrison was the strongest boxer he had faced. In July 2003, he lost the title to the Mexican Manuel Medina but regained it in November of that year. In May 2006 Harrison pulled out of a title defence in Belfast. Promoter Frank Warren was disappointed with the decision but urged Harrison to seek help for his problems. It was reported that an incident had occurred