Kom, who followed her most recent World Championship success in 2010 with an Olympic bronze medal at London 2012, had spent over a year out of the sport after winning gold at the 2014 Asian Games in Incheon.

Some had doubted the 32-year-old's ability to return to the top but she did so in fine style with a 3-0 points victory over Venezuela's Karlha Magliocco in her under 51 kilograms quarter-final.

Kom, one of India's best known Olympians, will next face United States' Virginia Fuchs for a place in the final in the Riocentro Pavillion 4.

Britain's Lisa Whiteside also made it through in the flyweight division and will now face home hope Grazieli Jesus De Sousa in the other last four clash, hoping to lay down a marker in the absence of Olympic champion team-mate Nicola Adams.

On a good day for Britain, Galal Yafai defeated Japan's Tomoya Tsuboi in the under 49kg division, Anna Cameron beat Venezuela's Mailin Barrera at under 60kg and Joshua Buatsi got the better of India's Devanshu Jaiswal at under 81kg.

Hotly rated under 60kg prospect Luke McCormack also beat Carlos Balderas of United States via a walkover.

France’s world bronze medallist Estelle Mossely beat Mexico's Americas champion Victoria Torres in the women's under 60kg event, while Morocco's reigning world champion was a comfortable points winner over Germany's Arajik Marutjan at under 69kg.

Another leading name to excel on day one was Uzbekistan’s unbeaten World Series of Boxing star Hasanboy Dusmatov, who inflicted further woes on Venezuela by beating under 49kg rival, Angelino Cordova.

Ecuador's Julio Castillo was another winner, beating Morocco's Abdeljalil Abouhamda in the under 91kg heavyweight category.

Action is due to continue over the weekend in the Brazilian city.

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