RIO DE JANEIRO, April 2 (Reuters) - Adriano scored in the fourth minute of injury-time to give Brazilian champions Sao Paulo a 1-0 win over Paraguay's Sportivo Luqueno in the Libertadores Cup on Wednesday. America beat River Plate 4-3 in a game which produced a remarkable sequence of five headed goals in 12 minutes, while Estudiantes and Lanus drew 3-3 in an all-Argentine clash in which both teams finished with 10 men. Rank outsiders Luqueno looked set to hold Sao Paulo for the second time in Group Seven at the Morumbi, packing their penalty area and making liberal use of time-wasting tactics. But they were thwarted when Adriano, on loan from Inter Milan, headed his third goal of the competition following a free kick, atoning for two glaring misses earlier in the second half. The Brazilians top the group with eight points from four games, four ahead of Luqueno and Colombia's Atletico Nacional. River Plate, who could have booked their second-round place with a match to spare by winning in Mexico, took a sixth-minute lead when Rodrigo Archubi scored from close range. The game swung after halftime with five headed goals between the 51st and 63rd minutes. Rodrigo Inigo and Enrique Esqueda scored twice in three minutes to put America 2-1 up, America's Diego Cervantes scored at both ends to make it 3-2 for the Mexicans before Sebastian Abreu equalised for River. Paraguay striker Sebastian Cabanas finally settled the game for America in the 69th minute with a shot on the turn. America and River have nine points from five games in Group Five while Chile's Universidad Catolica and Deportivo San Martin of Peru have six. There was also drama in Buenos Aires where Jose Sand and Diego Valeri put Argentine champions Lanus 2-0 ahead inside 15 minutes against Estudiantes, but the visitors to were level eight minutes later after Leandro Desabato and Leandro Benitez scored. Despite having Agustin Alayes sent off before halftime for a second bookable offence, Estudiantes went 3-2 up with a 61st-minute goal from Ivan Moreno y Fabianesi. Lanus equalised with a Lautaro Acosta goal in the 78th minute before having Santiago Hoyos dismissed eight minutes later for a wild tackle. Estudiantes top Group Two with eight points from five games, followed by Lanus on seven, Ecuador's Deportivo Cuenca on six and Uruguayan side Danubio on four. Brazil's Fluminense qualified for the last 16 for the first time, securing their place with two games to spare by beating Paraguayan champions Libertad 2-0 in Rio de Janeiro. Fluminense and Ecuador's LDU, also through, have 10 points from four games in Group Eight. Cicero and Thiago Silva were on target for Fluminense.