Palmeiras, lethal on the counterattack, beat Fluminense 2-1 on Wednesday to seize the upper hand in their Copa Libertadores semi-final tie.
Goals from Argentine forward Jose Manuel Lopez in the 45th minute and Maron Freitas in the 85th put the Verdao ahead at Maracana Stadium, where Wesley Nata's header breathed some life into host Fluminense's hopes in the tie.
Palmeiras host the return leg next Wednesday in Sao Paulo. The winners advance to the November 28 final at Estadio Centenario in Montevideo.
Argentinian outfit Estudiantes de La Plata host reigning champions Flamengo in the first leg of their semi-final on Thursday.
Estudiantes, the lone non-Brazilian side remaining, are trying to break Brazil's stranglehold on South America's top club competition.
Brazilian clubs have won the last seven editions of the tournament -- since Argentine club River Plate's 2018 triumph.
Fluminense dominated possession in the first half, but an electrifying counterattack finished off by "Flaco" Lopez gave Palmeiras the lead.
Against the solid defense of the Sao Paulo club, Fluminense's best chances were long-range efforts from Hulk, Nonato and Augustin Canobbio.
The pattern continued in the second half, as Fluminense took the initiative only to run into the wall of the Palmeiras defense.
Veteran Fluminense goalkeeper Fabio stopped a Felipe Anderson shot in the 81st but was helpless against Freitas.
Late substitute Nata pulled one back with a soaring header.
erc/ma-bb/sla