Ricardo Alvarez scored with a 20-meter shot Sunday to give Velez Sarsfield a 1-0 victory over Lanus and take the lead in the Argentina Apertura tournament.
Alvarez's winner came in the 60th minute and gives Velez 30 points - the same as Estudiantes. Both clubs have won nine of 14 matches, but Velez has scored more goals and has a better goal difference.
Estudiantes lost 2-1 on Saturday to Tigre. Five rounds remain in the season.
In other matches Sunday, Argentinos Juniors defeated San Lorenzo 1-0, Quilmes won 2-1 over Godoy Cruz, Independiente drew 1-1 with Olimpo and Racing defeated Newell's Old Boys 2-0. River Plate and Boca play the superclasico on Tuesday.
Independiente let a victory slip away. Independiente was leading 1-0 after a second-half goal by Carlos Matheu but allowed a stoppage-time equalizer from Carlos Salom.
Nicolas Blandi's first-half goal lifted Argentinos Juniors to a 1-0 victory over San Lorenzo. It was Argentinos Juniors fifth victory in seven games.
Last-place Quilmes defeated Godoy Cruz 2-1 for its first victory of the season. The game was played in an empty stadium, a sanction against the club after Quilmes' fans last week attacked a bus carrying the opposition team - Gimnasia.
Miguel Caneo scored the winner for Quilmes in second-half injury time. Santiago Raymonda opened the scoring for Quilmes and Jairo Castillo equalized from Godoy Cruz.
Racing's Gabriel Hauche scored 30 seconds from the end of regular time and Pablo Luguercio added another in stoppage time in the 2-0 victory.
In other weekend matches: Colon defeated Huracan 2-1, Banfield and Gimnasia drew 0-0, and Arsenal and All Boys drew 0-0.
Boca Juniors and River Plate square off on Tuesday in what is traditionally the biggest match of the season. However, this time it could be a dud.
River Plate is winless in seven games, prompting the firing this week of coach Angel Cappa. Boca coach Claudio Borghi has also talked about quitting in the midst of a poor season.
