Second-placed Lanus won 2-1 at Independiente despite missing a retaken penalty.
Velez, who were beaten by Uruguay's Penarol in the semi-finals of the South American Libertadores Cup last week, have 33 points from 17 matches, Lanus are on 32 and Godoy Cruz 28.
It might have been a different story, though, if goalkeeper Marcelo Barovero had not made two very good saves from Ruben Ramirez and Mariano Donda in the opening 10 minutes of the second half with the score 0-0.
"Now we have taken one of the candidates out of the way," Barovero told Futbol Para Todos.
"Luckily the team showed guts after the Libertadores loss," added striker Juan Manuel Martinez, who scored a brilliant opening goal in the 65th minute.
Martinez took possession at the corner of the box, skipped over a string of tackles before slotting home.
David Ramirez, who joined Velez from Godoy Cruz in January, added the second in the final minute when he took a cross from fellow substitute Guillermo Franco on his chest, swivelled and volleyed in off the underside of the bar.
At Independiente, midfielder Diego Valeri put Lanus ahead with an early free-kick for his ninth goal of the Clausura.
Mauro Camoranesi laid on the second for striker Mario Regueiro in the 75th before defender Maxi Velazquez headed a late consolation.
With the score 1-0, Lanus were awarded a penalty which Silvio Romero put away but the referee ordered it to be retaken for encroachment. Keeper Hilario Navarro dived well to save Romero's second effort.
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