Joshua claimed the IBF heavyweight championship in fine style in front of a massive crowd of up to 18,000 live on Sky Sports Box Office and Showtime in the USA.
The 26 year-old from Watford stepped up his game on the back of a solid first round to unleash a series of pinpoint straight right hands on the American.
Martin, 29, looked embarrassed as he went down for the first time in his career and quickly got to his feet to continue the fight. Another big right swung round from Joshua immediately and clipped Martin on the jaw again. The self-professed ‘Prince’ obviously hadn’t recovered from the initial shot and hit the deck for the second time.
Although Martin didn’t look terribly hurt, he stayed down far too long, and with Belgian referee Jean-Pierre Van Imschoot counted as clearly as possible – he ultimately reached the count of ten.
The O2 Arena erupted as ‘AJ’ sealed his defining victory that sets up potential blockbuster clashes with David Haye and Tyson Fury in the future.
An overwhelming pre-fight favourite, Joshua, now 16-0 with 16 stoppages, proved to be too hot to handle for Martin without having to answer any further questions about his chin and stamina.
Great Britain now boasts an impressive haul of 12 world champions, two in the top division, as WBC title holder Deontay Wilder prepares to defend his WBC belt against Alexander Povetkin next month.