River Plate hit top spot in the Argentine Clausura championship on Saturday after Mariano Pavone hit a second-half goal to secure a 1-0 win over Banfield.
Pavone burst through the defense and slid a left-footed finish into the net in the 70th minute to give River 18 points from nine games to top the standings, two ahead of defending champion Estudiantes and Olimpo.
Banfield's Marcelo Bustamente was sent off in the 90th minute.
Estudiantes drew 0-0 with San Lorenzo on Friday, while Olimpo had a 2-0 win at Colon earlier Saturday with goals from Nestor Bareiro in the 17th and Marcos Litre in the 68th.
Also Saturday, Arsenal and Quilmes drew 2-2 and Huracan played out a scoreless draw with Racing Club.
Olimpo took a temporary lead of the standings earlier Saturday, after Bareiro and Litre scored a goal in each half to earn victory at Colon.
A win would have moved either club level on points with Estudiantes but a red card for Colon's Maximiliano Caire in the 53rd made for a comfortable finish for Olimpo.
The fourth home defeat in a row was greeted by angry chants from Colon fans and the club later announced it had sacked coach Fernando Gamboa.
Elsewhere, Pablo Vazquez opened the scoring for Quilmes with a header in the 26th minute before Lisandro Lopez leveled for Arsenal.
Pablo Garnier put Quilmes back in front in the 83rd, but Luciano Leguizamon got Arsenal's second equalizer in injury time.
Quilmes stayed bottom of the table with three points, while Arsenal remained in the bottom half with 10.
On Friday, Independiente had a 3-0 win over Godoy Cruz to move into the top half of the table.
Fixtures continue Sunday, with Argentinos Juniors vs. Gimnasia, Lanus vs. Boca Juniors, Tigre vs. All Boys, and Velez Sarsfield vs. Newell's Old Boys.