Rodriguez put Newell's ahead with a shot in the 20th minute at the Marcelo Bielsa in Rosario and had a penalty saved by Pablo Migliore before halftime before Pablo Perez made sure for the home side with their second goal 20 minutes from time.
"The team are maintaining their essence and playing very well," Rodriguez told reporters as Newell's look to retain the title they won under then coach Gerardo Martino in June. Martino is now in charge of Spanish heavyweights Barcelona.
Newell's have 20 points from nine matches, one more than San Lorenzo, who beat Gimnasia 3-0 on Saturday.
Juan Antonio Pizzi's Saints, who count Pope Francis among their fans, are in rampant form with four wins in five matches scoring eight goals and conceding none.
Arsenal, the only unbeaten team, are third three points off the pace after their 1-0 home win over Godoy Cruz on Friday with Boca Juniors in fourth.
Racing Club's terrible season continued with a 3-0 defeat at Belgrano in Cordoba that keeps them pegged to the bottom of the standings with two points.
Belgrano striker Cesar Pereyra scored twice, his second goal a superb overhead scissors kick that gave goalkeeper Sebastian Saja no chance.
Racing are in deep trouble off the pitch too with the resignations of president Gaston Cogorno and vice-president Rodolfo Molina, who have been at loggerheads for weeks over the running of the club.
"I'm not affected by the political issue but maybe the players are," Racing coach Carlos Ischia told reporters.
"I'm worried we're not winning or scoring goals. We lack order and commitment."
Boca beat Quilmes 2-0 at La Bombonera to boost their confidence ahead of next Sunday's 'superclasico', Argentina's biggest club fixture, against arch-rivals River Plate, who were away to Lanus in a later match.
Striker Emmanuel Gigliotti scored once in each half, his first from a lobbed pass by Juan Roman Riquelme, making his comeback from injury after missing their previous four matches, the second a header from Juan Sanchez Mino's left cross.
Colon had three players sent off in their 1-0 defeat at Tigre, who also had a player dismissed, and the Santa Fe club's directors had to persuade coach Ruben Forestello not to quit after their fourth successive defeat.