Reigning Apertura champions Banfield were held to a goalless home draw in their early season top-of-the-table clash with Estudiantes.
Both clubs entered the match having won their opening two matches but neither could find a breakthrough to go clear at the top.
As a result they lead the fledgling table on seven points apiece, but could be overtaken at the weekend with Racing Club, Velez Sarsfield and River Plate all just a point behind.
Newell's Old Boys claimed their first win of the season 2-0 against nine-man Tigre.
Tigre, who are without a point, had Renzo Vera sent off after 41 minutes and went behind four minutes later when Rolando Schiavi netted.
Cristian Trombetta was shown the second red card of the game five minutes from the end before substitute Luis Rodriguez sealed the win in the 87th minute.