San Lorenzo won Argentina's Inicial championship after title rivals Newell's Old Boys were held 2-2 by Lanus.
The Saints Sunday drew 0-0 with Velez Sarsfield in the final round to finish with 33 points from 19 matches, two ahead of Velez, Newell's and Lanus, reports Xinhua.
Newell's looked poised to force a title playoff against San Lorenzo before Jorge Pereyra Diaz's 75th minute header tied the scores.
The title was San Lorenzo's 12th and first since 2007.