LONDON -- The best moments of Anthony Joshua's professional career have come in his past four fights ahead of his toughest test yet against Wladimir Klitschko on Saturday.
Only one opponent has briefly troubled Joshua, who last came close to losing in his final amateur bout at the 2012 London Olympics.
Since then, the Briton has stopped all 18 professional opponents ahead of facing Klitschko at Wembley Stadium.
ESPN looks at the IBF world heavyweight champion's most significant five fights.
Points victory vs. Roberto Cammarelle: Aug. 12, 2012, ExCeL Arena, London
Joshua won Olympic super-heavyweight gold on the final day of the Games in front of his home fans in London by out-pointing the Italian Cammarelle, the 2008 Olympic gold medalist. Joshua, 22, needed to produce a strong finish as he went into the third and final round trailing by three points. It was desperately close -- the judges scored the fight 18-18 with Joshua winning on countback. Afterward, Cammarelle blamed the judges for costing him a second successive gold medal. Joshua's feat was remarkable considering he had taken up the sport less than four years previously. "That medal represents my journey and the support from my team," said Joshua. "It is much more than a gold medal -- it is a life experience."
TKO7 victory vs. Dillian Whyte: Dec. 12, 2015, The O2 Arena, London
This was Joshua's toughest fight to date, but he survived the biggest crisis of his career to produce a stunning finish of his bitter rival in the seventh round. The pair's rivalry and bad feeling left Joshua willing to engage in a brawl. Joshua was hurt by a left hook in the second round, but after taking a round off he grew in confidence until he left Whyte in a heap on the canvas with a thunderous right uppercut. Victory saw Joshua lift the vacant British heavyweight title.
KO2 victory vs. Charles Martin: April 9, 2016, The O2 Arena, London
Martin walked to the ring wearing a crown, but he was quickly toppled in a first defense of the IBF world heavyweight title. As soon as Joshua started landing, he hurt the American, whom he knocked out in the second round to become world champion in his 16th professional fight. Martin was floored twice in the second round by right hands and failed to beat the count the second time. "I'm very humble," said Joshua, who became the fifth-quickest heavyweight to win a version of the world title. "Anyone's dreams are possible. Just follow your dreams."
TKO7 victory vs. Dominic Breazeale: June 25, 2016, The O2 Arena, London
Joshua cruised to a seventh-round victory over Breazeale in a first world title defense after twice flooring his American challenger. After setting a steady pace, Joshua exploded into action in the seventh round and Breazeale could not resist two vicious combinations. "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." Breazeale became just the second professional opponent to take Joshua beyond three rounds, but he had to manage with his right eye virtually shut. It was all over in the seventh when Breazeale was floored twice by combinations. He bravely got up after being decked by a left and a right, but after a blizzard of blows he was returned to the canvas and the fight waved off.
TKO3 victory vs. Eric Molina: Dec. 10, 2016, Manchester Arena, Manchester
With the fight against Wladimir Klitschko all lined up, Joshua made light work of his latest American challenger in a third-round win. The Briton successfully defended his IBF world heavyweight title for a second time with another brutal demonstration of his power punching to claim an 18th stoppage win from as many professional bouts. Klitschko watched on from ringside as Joshua forced the stoppage after first flooring the American Molina with a right to the jaw. Molina just beat the count, and when action resumed Joshua landed a quick flurry that prompted the stoppage. Joshua's April 29 date with Klitschko was then announced from the ring.