Lanus leapt to fourth in the Apertura with a 2-0 win at Independiente on Monday.
A goal in each half from Silvio Romero (38) and Gonzalo Castillejos (81), just seconds after he stepped off the bench, ensured the points went to the visitors.
That allowed them to jump above Racing Club, who were held to a 1-1 draw at struggling Tigre thanks to a late equaliser.
Racing looked set to claim all three points thanks to Bruno Zuculini's 42nd-minute goal, but Alejandro Donatti levelled a minute from the end as winless Tigre recorded their seventh draw in 12 Apertura matches.
Racing had substitute Claudio Corvalan sent off in the dying seconds.
