Uzbekistan's Shakhobidin Zoirov scored an upset victory over two-time Russian world champion Misha Aloian to win the Olympic boxing flyweight gold here Sunday.

Zoirov, 23, fought in flurries to frustrate his skilful opponent and win by unanimous decision, with the judges scoring it 30-27, 29-28, 29-28 in his favour.

The Uzbek fighter celebrated deliriously after the decision, hoisted onto the shoulders of one of his cornerman who then carried the fighter around the RioCentro arena.

But Aloian, the 2012 Olympics bronze medallist and world champion in 2011 and 2013, was left distraught by the loss.

The 27-year-old Armenian-born fighter appeared to be sobbing into his towel as he was led away from the ring by his coaches.