For almost an hour San Martín appeared to be heading for another defeat and their winless start to the season was continuing but a red card to Aldosivi defender Ismael Quílez turned the game and in the space of a few minutes, Los Verdinegros were ahead.
Aldosivi themselves have only won the once but made the perfect start when Joel Acosta headed them in front after nine minutes.
However, the decisive moment came shortly after half time when Maxi Lugo’s charge towards the Aldosivi penalty area was halted by a tug of the shirt from Quílez. Héctor Paletta eventually brandished a red card to the correct player and within minutes of the decision, El Tiburón were behind.
Diego Cháves fired in an equaliser and two minutes later a quickly taken free kick found Emanuel Dening and the 28-year-old smashed a volley past Matías Vega from the edge of the penalty area.
With one win apiece both sides still languish near the foot of the table but for the timebeing have a little breathing space in the descenso.
Aldosivi 1 – 2 San Martín