With Deportivo Tachira's game at Llaneros de Guanare suspended at half-time due to severe rain, Mineros could have moved into first position in the standings with a home win over recently-promoted Portuguesa but had to come from behind just to earn a 1-1 draw.
The draw saw last season's runners-up join four other clubs on four points at the top of the Primera Division with Deportivo La Guaira ahead on goals scored.
But Mineros could have maintained a perfect start to the Apertura campaign and taken an overall lead with a victory over Portuguesa, who finished second in the Segunda Division last season to gain promotion to Venezuela's top tier.
Mineros had opened their season with a 1-0 win over the other promoted club Metropolitanos last week but fell behind after just 18 minutes at home on Sunday when Portuguesa's Jose Villafraz curled his free-kick over the wall and into the bottom corner.
Metropolitanos versus Aragua, Estudiantes against Zamora and Tucanes' visit to Petare all finished 1-1, while Atletico Venezuela defeated Zulia 1-0.
