Everton capitalised on a Renato Chaves error to blast an angled shot into the top left corner just after the half-hour mark during Sunday night's game, reports Xinhua news agency.
The result at the iconic Maracana Stadium means Flamengo need only a draw in next Sunday's return leg -- at the same venue -- to claim the Rio state title for the 34th time.
In Sao Paulo, Corinthians moved to within touching distance of their 28th Paulista championship title after a 3-0 away victory over Ponte Preta in the first leg of the final.
Rodriguinho netted either side of halftime while former Brazil midfielder Jadson was also on the score sheet with a 59th-minute strike at the Moises Lucarelli Stadium in Campinas.
The Paulista championship is the top division professional league in the state of Sao Paulo.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
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