Rubuta ci gaba ga wannan sakin layi - 2011 ya ga Harrison ya ci gaba a matakin babban jami'in. Ya lashe gasarsa ta farko a gasar cin kofin duniya ta UCI Track a Beijing, inda ya lashe omnium. Harrison ya fara fitowa a gasar zakarun duniya ta UCI a shekarar 2011
, wanda ya lashe lambar tagulla a matsayin wani ɓangare na Team Pursuit. An zaba shi a wasan karshe bayan da Ed Clancy ya kamu da rashin lafiya. Harrison kuma ya gama 11th a cikin omnium.