Rio Olympics 2016: Claressa Shields retains women's middleweight Olympic gold

American Claressa Shields retained her Olympic title as she beat Nouchka Fontijn of the Netherlands in the women's middleweight final in Rio.

Shields, 21, won by a unanimous points decision to become the first American, male or female, to win back-to-back Olympic gold medals in boxing.

Fontijn defeated Great Britain's Savannah Marshall in the quarter-finals but was outclassed in the final.

Shields' gold medal is the 44th for the United States at the 2016 Olympics.

One judge gave her the verdict by 40-36, with the other two scoring it 39-37 in her favour.

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