Neymar hit the post twice as Santos was held to a scoreless draw at Corinthians in the Sao Paulo state championship Sunday.
Elsewhere, Gremio took a 3-2 lead against Internacional in the first leg of the Rio Grande do Sul state final, while Atletico Mineiro took a 2-1 advantage over Cruzeiro in the Minas Gerais state final.
The return matches are next weekend.
Neymar, the latest Brazilian football sensation, clipped the right post in the 23rd minute against Corinthians with an angled shot from close range.
The 19-year-old striker looked Santos' best hope of breaking the deadlock and went close again in the 75th when his shot bounced off the crossbar and went over.
In the Rio Grande do Sul final, Junior Vicosa, Leandro and Lins got the goals in Gremio's win at Internacional.
Meanwhile, former Inter Milan midfielder Mancini was on the scoresheet for Atletico Mineiro in the Minas Gerais final against Cruzeiro.
Brazil does not follow the European football calendar and the Brazilian league won't start until the third week of May. In the first few months of the year teams play regional tournaments in each of the country's 26 states, in addition to the Brazilian Cup.
In Argentina, Velez Sarsfield enjoyed a good day without playing as River Plate wasted an opportunity to take a temporary lead of the Clausura championship standings.
River was downed by lowly All Boys, with Emanuel Gigliotti and Juan Rodriguez getting the goals in a 2-0 win.
The result left Velez atop the table with a game in hand. Godoy Cruz, which won 3-1 at Newell's Old Boys on Friday, moved to second, with Olimpo ahead of River on goal difference a point further back.
Boca Juniors moved up to 11th on 18 points after Martin Palermo and Juan Roman Riquelme notched first-half goals in a 2-0 win at Argentinos Juniors.
Defending champion Estudiantes faltered again with a scoreless draw at Lanus, which had Mario Regueiro sent off in the 65th.
Estudiantes is a place below Boca Juniors on goal difference.
In Mexico, UNAM Pumas provided the upset of the playoff quarterfinals with a 2-0 home win in the return leg to eliminate reigning champion Monterrey.
Monterrey had taken the first leg 3-1, but goals from Efrain Velarde and Luis Fuentes put Pumas through.
Pumas will play Chivas in the semifinal after the Guadalajara side got a 1-1 draw at UANL Tigres on Saturday to back up a 3-1 win in the first leg.
Cruz Azul also progressed Saturday after a scoreless draw in the second leg against Atlante completed a 2-1 aggregate win.
The Mexico City club will face Morelia, which beat America 3-2 on Sunday.
Elsewhere in Latin America, Universidad Catolica took a stranglehold on the Chilean Apertura tournament after holding out for a scoreless draw against Union Espanola despite finishing the match with nine men.
Catolica leads Universidad de Chile, which won 3-1 at Huachipato, by five points with three matches remaining before the playoffs.
In Uruguay, Nacional defeated archrival Penarol 1-0 with a goal from Santiago Garcia to move atop the Clausura standings after the 12th round of fixtures.
In Colombia, Once Caldas had a 2-1 win against Atletico Huila to become the first club through to the playoffs in Colombia's Apertura tournament.
