Last updated on .From the section Boxing

Women's boxing: History-maker Claressa Shields tops the bill

Olympic champion Claressa Shields won by knockout in the first women's boxing match to headline a premium television event in the United States.

The American, 21, who won middleweight gold at London 2012 and Rio 2016, turned professional in October.

Shields stopped Hungary's Szilvia Szabados with a strong punch in the fourth round in Detroit to take the North American Boxing Federation title.

She previously won her first professional fight in November.

The fight - which topped the bill - aired on Showtime, a premium channel which requires traditional cable subscribers to pay an additional fee.

"I wasn't just out there brawling with her - I showed my skill, I showed my power," Shields said.

"I showed how I box like Sugar Ray Robinson and Joe Louis mixed together.''