Goalkeeper Felipe made two penalty saves to help Flamengo defeat Botafogo 3-1 in a shootout in the semifinal of the Guanabara Cup on Sunday.
Brazil's most popular club will now play Boavista, which stunned Brazilian champion Fluminense in another penalty shootout after a 2-2 draw in regulation time on Saturday.
Ronaldinho's Flamengo drew Botafogo 1-1 in regulation at Engenhao stadium, with Ronaldo Angelim scoring for Flamengo in the 14th minute and Uruguay striker ''El Loco'' Abreu equalizing in the 49th.
The Guanabara Cup is the first stage of the Rio tournament, and its winner will play for the Rio state title against the Rio Cup champion.
In Sao Paulo, Palmeiras stayed atop the standings after a 0-0 draw at Mogi Mirim.
Felipe stopped the shots of Everton and Somalia, and midfielder Renato Caja sent Botafogo's final penalty wide to seal Flamengo's victory. Leo Moura, Renato and Fernando all scored their penalties for Flamengo.
Angelim gave Flamengo the lead with a header off a corner, but Abreu equalized with a shot from near the penalty spot to send the match into the shootout.
Ronaldinho was held scoreless but created some significant scoring chances. His best opportunity was with an injury-time free kick that was saved by goalkeeper Jefferson.
On Saturday, Fluminense was heavily favored to advance from its semifinal against Boavista at Engenhao but lost 4-2 in the shootout thanks in part to a missed penalty by Argentine playmaker Dario Conca, the most valuable player when Fluminense won the Brazilian title last year.
Boavista twice came from behind in the 2-2 draw in regulation. It only reached the semifinals because Vasco da Gama struggled in the group stage and was eliminated.
Fluminense was still without former Chelsea playmaker Deco and striker Emerson because of injury.
The one-match Guanabara Cup final will be next Sunday at the Engenhao. Maracana stadium is not being used because of renovations ahead of the 2014 World Cup which will be played in Brazil.
In the Sao Paulo state tournament, former Sporting striker Liedson scored his fifth goal in four matches to give Corinthians a 3-1 victory over Santos. Left back Fabio Santos scored the other two Corinthians' goals off a penalty kick and a free kick.
Brazil midfielder Elano scored the lone goal for Santos, which was yet to lose in its first 10 matches in the Sao Paulo championship.
Recently retired striker Ronaldo was honored by fans before the match at Pacaembu stadium, and all Corinthians players wore jerseys with numbers that included ''9'' on them.
Luiz Felipe Scolari's Palmeiras failed to get past a scoreless draw at Mogi Mirim, but it remained atop the standings with 20 points, one more than Corinthians and two more than both Sao Paulo and Santos.
The top eight teams will advance to the quarterfinals of the Sao Paulo tournament.
Sao Paulo routed Bragantino 4-0 at Morumbi stadium on Saturday despite a missed penalty kick by goalkeeper Rogerio Ceni, who is seeking his 99th career goal.
One of Sao Paulo's goals was scored by young midfielder Lucas, one of Brazil's most talked-about players after helping Brazil win the under-20 South American championship earlier this month in Peru. Lucas has just extended his contract with the Brazilian club, and now it includes an ?80 million ($58 million) buyout clause, one of the biggest in Brazil.
Also Saturday, Copa Libertadores champion Internacional fell 5-4 in a penalty shootout against local club Cruzeiro to be eliminated from the Rio Grande do Sul state tournament. Inter played with its second-stringers because it is focused on this year's Latin American competition.
