Olympics boxing: Claressa Shields takes middleweight gold for USA

American teenager Claressa Shields has won the inaugural women's 75kg middleweight crown at London 2012.

The 17-year-old overcame Nadezda Torlopova, 33, of Russia to take the final 19-12 (3-3 7-4 5-3 4-2).

Shields defeated Marina Volnova of Kazakhstan en route to the final, who in turn beat Great Britain medal hope Savannah Marshall in the last eight.

Shields, from Flint, Michigan, becomes the second youngest boxer ever to win Olympic gold.

Fellow American John Fields was 16 when he won the featherweight title at the 1924 Games in Paris.

She also doubled her nation's boxing medals tally at these Games - the only other United States fighter to have claimed a prize is lightweight bronze medallist Marlen Esparza.

Torlopova enjoyed most success in the opening round, but faded badly to pave the way for Shields' success.

The two bronze medallists in the weight division were 23-year-old Volnova and Jinzi Li of China.