Anthony Joshua cruised to a seventh round victory over Dominic Breazeale in his first world title defense on Saturday night. The 26-year-old Briton floored his American challenger twice in the seventh round as he retained his International Boxing Federation (IBF) heavyweight title and extended his remarkable run of knockouts at the O2 Arena in London.Joshua, who has stopped all 17 professional opponents since winning an Olympic gold medal at London 2012, inflicted Breazeale's first professional defeat in his 18th bout after controlling the fight from start to finish. "When I started catching him flush you know it's beginning to work," said Joshua. "He was patient, avoiding my punches, and I had to take my time. Now I need a rest, it's hard work doing this." Joshua is expected to make a mandatory defense against New Zealand's Joseph Parker by the end of the year or spring 2017.Clashes against rival world champions, or fellow Briton David Haye, are likely to be next year at the earliest for Joshua, who is increasingly looking like the man to beat in the heavyweight division. Joshua's fellow Briton Tyson Fury will defend his World Boxing Association (WBA) and World Boxing Organisation (WBO) belts against former lineal champion Wladimir Klitschko later in the year now after spraining an ankle, while Deontay Wilder defends his World Boxing Council (WBC) title against fellow American Chris Arreola on July 16.