Gabriel scored in the 42nd minute, Luan added a goal in the 47th and Brazil beat the United States 2-1 in an under-23 exhibition game Wednesday night in Recife, Brazil.
Jerome Kiesewetter converted a penalty kick in the 60th minute for the Americans, who are preparing for a two-leg playoff against Colombia in March for a berth in next year's Rio de Janeiro Olympics.
The U.S starting lineup included defender John Brooks and midfielder Julian Green, who both scored for the Americans against Belgium at last year's World Cup in Brazil.
The U.S. and Brazilian under-23 teams meet again Sunday in Belem.
Venues and dates for the men's and women's Olympic football matches were released Tuesday.