Taylor Townsend became the first American girl in 30 years to finish No. 1 in the year-end world junior rankings.
The 16-year-old Townsend lost to seventh-seeded Ana Konjuh of Croatia 4-6, 6-1, 6-3 Saturday in the semifinals of the Orange Bowl International Tennis Championships. But she clinched the top ranking when No. 3 Katerina Siniakova lost in the Orange Bowl doubles quarterfinals.
Gretchen Rush was the last American girl to end the year as ITF world junior singles champion in 1982.
Townsend, of Stockbridge, Ga., trains with U.S. Tennis Association national coach Kathy Rinaldi at the player development center in Boca Raton, Fla.
Townsend won the 2012 Australian Open singles and doubles titles, along with doubles titles at Wimbledon and the US Open.
She plans to turn pro in 2013.