World number one Rishod Sobirov maintained his 18-month unbeaten run by qualifying for the semi-finals of the World Judo Championships here on Tuesday. The king at under-60kg from Uzbekistan made short work of Azerbaijan's Ilgar Mushkiyev in the semi-finals, scoring the maximum ippon score with a foot-sweep (de-ashi-barai). The world champion has won his last six major tournaments, including the Masters in January and three Grand Slams. He started the day with a bye and then beat Switzerland's Ludovic Chammartin and Hermann Zoungrana of Burkina Faso before submitting Brazil's Felipe Kitadai to reach the quarters. It wasn't such a good day for world number two Georgii Zantaraia of Ukraine who was narrowly beaten by a penalty in the last eight by South Korea's Choi Gwang-Hyeon. Choi was one of two Koreans to reach the last four as Kim Won Jin upset world number four Hirofumi Yamamoto of Japan in the last 16 and then dumped Russia's Arsen Galstyan, ranked five, in the quarters with a drop shoulder throw (ippon-seoi-nage). Kim will take on Sobirov in the afternoon's semis while Choi will tackle world number three Hiroaki Hiraoka of Japan. He was 11 seconds away from defeat to home hope Issam Nour in the last 16 before producing a brilliant inner leg sweep (kouchi-gari). Hiraoka, a former world championship finallist, then beat Armenia's Hovhannes Davityan in the quarters with another stunning technique, the stomach throw (tomoe-nage). In the men's under-66kg division there were shocks aplenty as world number one Khashbaatar Tsagaanbaatar of Mongolia and Japanese world champion Junpei Morishita both bit the dust. Tsagaanbaatar was narrowly beaten in the last 16 by South Korea's Cho Jun-Ho who was then in turn beaten by Japan's Masashi Ebinuma. He will face world number four Musa Mogushkov in the last four following the Russian's quarter-final victory over Azerbaijan's Tarlan Karimov. Morishita injured his elbow in the third round as he was trying to resist an armlock by Moldova's Igor Soroca. The injured world number two then attacked with a weak inner-thigh throw (uchi-mata) which was countered (sukeshi) for ippon. However, Soroca lost to Britain's Colin Oates who then in turn was thrown for ippon by Brazil's Leandro Cunha with a delicious uchi-mata. Cunha will face Slovenia's Rok Draksic in the last four after the latter's dramatic two-legged foot-sweep to beat France's David Larose in the quarters. Japanese pair Haruna Asami and Tomoko Fukumi remain on course to contest a repeat of the 2010 world final in the women's under-48kg category. Reigning champion and world number one Asami made short work of quarter-final opponent Wu Shugen of China with a low uchi-mata for ippon. Fukumi, world number two and 2009 world champion, was equally impressive with her sukeshi counter to defeat French veteran Frederique Jossinet in the quarters. Fukumi will face Belgian groundwork (ne-waza) specialist Charline Van Snick who upset Olympic champion Alina Dumitru of Romania in the last eight. Asami will face Brazil's Sarah Menezes after she despatched Hungary's Eva Csernoviczki in just 18 seconds.