Olympics-Boxing-Russia's Tishchenko wins heavyweight gold

* Russia win heavyweight gold * Levit takes silver for Kazakhstan (Adds details) By Alan Baldwin RIO DE JANEIRO, Aug 15 (Reuters) - Russia's Evgeny Tishchenko won the Olympic heavyweight boxing gold medal to a chorus of boos from the crowd on Monday after beating Kazakhstan's Vasily Levit on a unanimous points decision. Levit, whose taller and longer-reached opponent required medical attention for a cut in the third and final round and who had been backed repeatedly on to the ropes, took the silver medal. The bronze medals went to losing semi-finalists Rustam Tulaganov of Uzbekistan and Erislandy Savon of Cuba. The majority of the audience, in a Riocentro arena that was barely half full, reacted to the score announcement with derision while a pocket of Russian fans waved flags and celebrated. The judges scorecards had Levit narrowly ahead after the first round, with two out three giving it to the Kazakh, but they were unanimous in giving the second to the Russian. Levit came on strong in a scrappy third round, with both men hitting out wildly and Tishchenko slipping and losing his balance. The referee called a halt with 51 seconds remaining for inspection of a cut, before the fight resumed and ended in a flurry of punches. Russian athletes have been regularly booed in Rio as a result of the country's doping scandal that has overshadowed the Games. (Editing by Ed Osmond)