Newell's Old Boys took a 1-0 lead through Ignacio Scocco's goal in the 10th minute, but Mauro Obolo equalized for the hosts in the 79th.
In other matches Sunday, Quilmes was held 2-2 at home by Colon while River Plate drew 0-0 at All Boys.
Saturday's matches ended: Argentinos Juniors 1, San Martin 1; Union 2, Estudiantes 2; Boca Juniors 3,
San Lorenzo 1; Arsenal 1, Velez Sarsfield 5.
On Friday, Belgrano won 3-1 at Atletico Rafaela and is now only two points off the lead.
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