data-mm-id=”_vjxw4rd7l”>Alex Pereira stands 6-foot-4 and is the reigning champion of the UFC's light heavyweight division at 205 pounds. He has defended his title twice, most recently in June when he scored a second-round TKO of Jiri Prochazka at UFC 303.In pound-for-pound rankings that assess fighters regardless of weight class, Pereira is a consensus No. 2 selection behind Islam Makhachev, the UFC's lightweight champion.On Friday, Pereira was second-best … to a YouTube star listed at 5-9.Pereira went head-to-head with IShowSpeed, a 19-year-old live streamer whose real name is Darren Jason Watkins Jr., in a test of punching strength on the UFC Striking Challenge machine.Pereira went first and registered a punch of 907. IShowSpeed stepped up next and shockingly surpassed Pe…