Velez Sarsfield, runners-up to Estudiantes in the Apertura championship in the first half of the season, came from two goals down to draw 2-2 at Independiente.
Estudiantes, who appointed Eduardo Berizzo as coach on Tuesday in response to Sabella's shock resignation, scored the opening goal of the championship in the 13th minute.
Striker Gaston Fernandez slotted home first time from winger Enzo Perez's perfectly weighted pass into the box.
Perez also laid on the second for right-back Gabriel Mercado in the 24th minute with a fine cross-field ball from deep on the left.
Estudiantes could have been three-up at the break but Newell's goalkeeper Sebastian Peratta saved Fernandez's penalty in the 43rd minute after defender Rolando Schiavi had pulled Perez back by his shirt.
The champions lost some shape in the second half as Newell's forced the pace trying to get back into the game but they left their chances till too late.
Striker Claudio Bieler blasted the ball over the bar from a good position two minutes from time and substitute Juan Manuel Cobelli netted a consolation goal in the 90th from Mauricio Sperdutti's low cross.
KEEPER'S BLUNDER
Independiente shocked Velez by taking a two-goal lead in the first half at their Libertadores de America ground in the suburb of Avellaneda, both goals coming from set pieces.
Striker Juan Manuel Parra netted from close range in the seventh minute and midfielder Roberto Battion scored from a similar position when right-back Maxi Velazquez headed the ball back into the centre from a free-kick.
Velez pulled a goal back 70 seconds into the second half when Augusto Fernandez's chip over the defence beat the offside trap and little midfielder Maxi Moralez raced through to shoot across goalkeeper Hilario Navarro's body.
Navarro's blunder in the 79th minute gifted Velez their equaliser.
He appeared to have caught a cross but then lost the ball. Defender Emiliano Pappa headed into middle for substitute Juan Manuel Martinez, fresh from his Argentina debut against Portugal in Geneva on Wednesday, to score.
