World champion Wladimir Klitschko has issued a warning to any fighters looking to step up to the heavyweight division to think twice after he knocked out Jean-Marc Mormeck. The 35-year-old defend his IBF, IBO, WBO and WBA titles, needing just four rounds to knock-out Mormeck, who stepped up from cruiserweight two years ago, and made good his promise to make the Frenchman the 50th KO of his career. Last July, Klitschko beat Britain\'s David Haye, who had also stepped up from cruiserweight, to claim the WBA title. The champion said promising cruiserweights and light heavyweights to carefully consider any challenge for a world heavyweight title. \"I think all the light heavyweights who have ambitions to get into heavyweight division should think twice,\" he said, having claimed the 57th win of his career with just three defeats in 60 fights. \"Jean-Marc wanted to believe I was weak at this point but I wanted to prove that my chin was solid,\" he added after Mormeck had threatened to \"smash\" the Ukrainian\'s \"glass-jaw\" in the pre-fight build up. \"From the first round, I set the pace and I controlled the fight the whole time. \"I expected him to come forward and I also knew he had no chance of succeeding with his plan. He insisted on it, however, and the end was inevitable.\" Mormeck, who turns 40 in June, was put on the canvas as early as the second round and despite rallying in the third, Klitschko finished the fight with a combination mid-way through the fourth before the referee stepped in. \"I think Jean-Marc was surprised by the strength, speed and balance of my boxing right off the bat,\" said Klitschko. \"I think he didn\'t expect it and it was difficult for him to restart after the first shot that I landed on him in the second round.\" Mormeck barely landed a decent shot all night and Klitschko\'s one-sided victory did little to improve the image of the sport that was tarnished by last month\'s press conference brawl between Haye and Dereck Chisora. \"This was an execution without sporting value,\" said former European champion Luan Krasniqi after the fight. With no serious heavyweight contenders in the United States, it remains to be seen who can challenge the Klitschkos domination of the division, with Wladimir\'s elder brother Vitali holding the WBC belt. Russia\'s Alexander Povetkin was disappointing in his recent points win over Marco Huck and in July Wladimir has a mandatory defence of his IBF title against 40-year-old American Tony Thompson, who he already knocked out in 2008.