Boca Juniors struggled to a 0-0 draw at Union on Sunday to leave the famous Buenos Aires club without a goal in its last two matches.
The lifeless draw could keep the pressure on Boca coach Julio Cesar Falcioni, who has felt the pressure for almost a week following a run-in with some of his top players after a 0-0 draw with Venezuela club Zamora in the Copa Libertadores.
Boca is undefeated in 33 matches, but current form is worrying many hardcore fans.
Lanus became the only club in Argentina with a perfect record after just two rounds of the Clausura tournament with a 1-0 victory Sunday against Independiente. Mariano Pavone scored in the 86th for Lanus.
Boca has four points in its first two matches.
In other matches on Sunday, Godoy Cruz defeated Racing 1-0 thanks to Leonardo Sigali's goal in the 84th.
Nestor Ortigoza scored in the 55th to give relegation-threatened San Lorenzo a 1-1 draw with Estudiantes. Christian Cellay gave Estudiantes a 1-0 lead in the 17th.
Neither Boca nor Union produced many good chances. Boca picked up four yellow cards in the first half, but failed to generate much of anything else.
Union defender Juan Cardenas probably had the best chance in the match with a twisting shot in the 56th that was batted away by Boca keeper Agustin Orion.
On Friday, Olimpo defeated Belgrano 4-1, and Velez won 4-0 at Velez.
On Saturday, Newell's defeated Argentinos Juniors 1-0, Arsenal and Rafaela drew 2-2, and All Boys beat Colon 2-0.
Tigre play San Martin on Monday. San Martin won its first match and could keep pace with Lanus with a victory.
