Carlos Bueno's 38th-minute goal gave Belgrano their third straight league victory and will see them end the Torneo Inicial in sixth spot.
With the top four, who are all vying for the title, having their matches pushed back to Sunday, Arsenal ensured they would finish fifth.
Mariano Echeverria cancelled out Lucas Albertengo's opener as Arsenal rescued a point in a 1-1 draw at Atletico Rafaela.
Boca Juniors were held to a 1-1 draw at home to Gimnasia La Plata while Estudiantes were beaten 2-0 at home to Tigre.
Walter Acuna struck a 61st-minute winner to lead Rosario Central to a 2-1 win at Argentinos Juniors and Godoy Cruz suffered a surprise 2-0 loss at Racing Club.
David Vega scored a dramatic late goal as Olimpo edged lowly Colon 1-0, while Quilmes and River Plate played out a 1-1 draw.
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