TOKYO, July 28 (Reuters) - Japan"s double world champion judoka Chizuru Arai triumphed in the women"s -70 kg category on Wednesday, beating Michaela Polleres of Austria in a gruelling final and earning the host nation its sixth judo gold. The Japanese team have won judo gold medals for five straight days and are just two short of their record of eight, set in Athens in 2004. Sanne Van Dijke of Netherlands and Madina Taimazova of the Russian Olympic Committee won the bronze medals. Arai, 27 years old and fifth in the world rankings, won her preliminary match by ippon - judo"s equivalent of a knockout - and the quarter-final, against German Giovanna Scoccimarro, with two waza-ari manoeuvres. She struggled to impose herself in the semi-final however, taking more than 16 and a half minutes before winning with a sliding lapel choke against Taimazova. "As the coronavirus delayed the Olympics, I had a feeling that what I had clinched was slipping away, but my rivals around the world continued training under such circumstances so I tried to keep up with them," Arai said. "I appreciate the fact that the Games came true thanks to support from many people despite various opinions about going ahead under severe circumstances." In the men"s -90 kg division, Georgian Lasha Bekauri took gold, beating Eduard Trippel of Germany in the final. Davlat Bobonov of Uzbekistan and Krisztian Toth of Hungary took the bronzes. Japan"s Shoichiro Mukai, who had been fancied to do well in the category, suffered a shock loss to Toth in the last 16.