RIO DE JANEIRO — Javier Cabrera scored a first-half goal on Thursday and Peñarol pulled off an upset after beating Flamengo 1-0 at home in the first leg of their Copa Libertadores quarterfinal match. Peñarol defeated Flamengo at Maracana stadium in a Copa Libertadores match for the first time since 2019, when they faced off in the group stage. Peñarol, …