US skipper Horan headed home in first-half injury time at San Diego's Snapdragon Stadium to settle a largely lacklustre finale to the 12-team tournament.
Bia Zaneratto scored twice as Brazil thrashed Argentina 5-1 on Saturday to move into the semi-finals of the CONCACAF Women's Gold Cup while Olympic champions Canada scraped past Costa Rica with a 1-0 win after extra-time.
US skipper Horan headed home in first-half injury time at San Diego's Snapdragon Stadium to settle a largely lacklustre finale to the 12-team tournament.
Bia Zaneratto scored twice as Brazil thrashed Argentina 5-1 on Saturday to move into the semi-finals of the CONCACAF Women's Gold Cup while Olympic champions Canada scraped past Costa Rica with a 1-0 win after extra-time.