Lanus triumph at Independiente to go top
Lanus are the only team with a maximum six points after two rounds of the season's second championship, while champions Boca Juniors drew 0-0 at Union, Racing Club and Independiente both lost 1-0 and San Lorenzo were held 1-1 at home by Estudiantes.
Boca have conceded a mere six goals in 21 matches this season, 19 in the Apertura championship they won in December, but Sunday's performance failed to dispel concerns even among their own players about a lack of sparkle in attack.
An internal squabble midweek almost ended with coach Julio Cesar Falcioni resigning after a slanging match with leading players over the team's poor 0-0 draw with modest Zamora in their opening Libertadores Cup match.
"It's past, the coach and the captain [Juan Roman Riquelme] have spoken," Boca goalkeeper Agustin Orion said as he tried to put the conflict behind Boca.
"Let's hope the result will be good for us in the long run (but) we have to improve," he told reporters with a phrase often used by playmaker Riquelme, the team's biggest critic.
Racing began the championship full of hope with former Argentina coach Alfio Basile in charge but have taken only one point from two matches and not yet scored after Sunday's 1-0 away loss to 10-man Godoy Cruz in Mendoza.
Godoy Cruz had midfielder Juan Carlos Falcon sent off in the 38th minute for pushing Racing's Colombian playmaker Gio Moreno in an off-the ball incident but scored through defender Leonardo Sigali six minutes from time.
Independiente's home match with Lanus appeared to be heading for a scoreless draw until former River Plate striker Mariano Pavone ran onto a ball through the middle of the defence to steer it home three minutes from time for his third goal in two league games.
Relegation-threatened San Lorenzo played better than last weekend when they were crushed 4-1 at Lanus but only managed a 1-1 draw with 10-man Estudiantes at their Nuevo Gasometro ground.