Independiente, battling to avoid relegation for the first time, ended a run of seven matches without a victory when they beat Argentinos Juniors 3-1.
At the Marcelo Bielsa stadium in Rosario, hosts Newell's were pegged back twice by Racing, teenage striker Luciano Vietto hitting a hat-trick for the visitors, while a player from each side was sent off.
The win put Newell's on 25 points from 11 matches, three points clear of Lanus, who can catch them on Monday if they beat Atletico Rafaela at home.
River Plate are third on 21 after giving away a late equaliser in a 1-1 draw at home to Quilmes.
Newell's raced into a two-goal lead in the opening half hour, Milton Casco opening the scoring before the championship's joint top scorer, Ignacio Scocco, converted a penalty to take his tally to seven.
Racing then had winger Diego Villar sent off for a bad foul on Casco but despite the setback Vietto scored either side of halftime, his first a neat lob, to pull the visitors level at 2-2.
Midfielder Pablo Perez restored Newell's lead in the 48th minute before the home team were also reduced to 10 men when Casco was sent off.
Vietto notched his third in the 61st minute to level the score at 3-3.
Newell's central defender Santiago Vergini hit the bar before Maxi ran onto a diagonal pass and steered a right-footed shot past goalkeeper Sebastian Saja inside the far post a minute into added time.
"We complicated the match ourselves," Newell's coach Gerardo Martino told reporters. "We had chances and we didn't finish many because we fell in love with our moves and didn't make sure with the final pass."
RELEGATION BATTLE
At the Monumental, River went ahead in the 54th minute as centre-back Eder Balanta headed home from a free-kick to notch his second goal in as many matches.
The home side enjoyed greater possession but paid for their failure to increase their lead when Quilmes' Martin Cauteruccio equalised a minute from time.
"Let's hope we finish the tournament with Quilmes in Primera (first division)," Cauteruccio said.
Former South American champions Independiente are in the bottom three of the relegation standings, a separate table based on teams' average points over three seasons, with three teams to go down. Quilmes are fourth from bottom.
Defender Leonel Galeano headed Independiente in front in the 52nd minute from a corner before Argentinos substitute Reinaldo Lemos fired a brilliant equaliser into the top corner 10 minutes later.
Midfielder Rolfi Montenegro restored Independiente's lead with a well-taken penalty in the 78th minute and less than three minutes later they made sure of the three points with a fine finish from young striker Adrian Fernandez.
Argentinos had Julio Barraza sent off in the 83rd minute for elbowing substitute Juan Caicedo in the box at a throw-in.
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