TOKYO, Aug 5 (Reuters) - Japan’s Nikkei index ended higher on Thursday, underpinned by upbeat earnings from Nippon Yusen , Kikkoman Corp and Hitachi Zozen, although gains were capped by concerns about surging cases of COVID-19. The tech-heavy Nikkei share average ended the day 0.52% higher, outpacing a 0.39% advance in the broader Topix , as technology shares tracked a firm finish on Wall Street. The Topix growth index added 0.62%, outstripping the value index’s 0.18% increase. Sea transport was the top subsector on the Topix by far, surging 9.5%. Nippon Yusen was the Nikkei’s best performer, jumping 12.7%. Fellow shippers Mitsui OSK Lines rallied 6.66% and Kawasaki Kisen jumped 6.58%. Sauce maker Kikkoman surged 9.93%, while infrastructure and energy company Hitachi Zozen rallied 6.81%. Elsewhere, Rakuten Group advanced 8.38% after the company entered a partnership to build a new mobile network in Germany. “There continue to be concerns that Japan’s stock market is top-heavy, but a string of positive earnings seems to have improved sentiment,” said a market player at a domestic securities firm. The Nikkei has steadily retreated since surging to a multi-decade high above 30,000 in mid-February, and has oscillated in a range of around 27,300-28,000 since mid-July, the start of a fifth wave of coronavirus infections. Japan reported an unprecedented 14,207 jump in new cases on Tuesday, led by a record 4,166 infections for Olympics-host Tokyo. Disappointing financial results from Ricoh also dragged the index on Thursday, tumbling 11.46%. (Reporting by Tokyo markets team; editing by Uttaresh.V and Ramakrishnan M.)