Forward Tiago Caeiro scored only his second goal of the season to earn a point that sees Lito Vidigal's men leapfrog Olhanense into 15th place, while Pacos move above Arouca into 13th.
It had looked as if the hosts were on their way to a 14th defeat of the campaign when on loan Manchester United forward Bebe gave Pacos the lead eight minutes into the second half.
The 23-year-old netted his fifth goal in as many games in spectacular fashion, hitting the target with a stunning free-kick from distance.
But 16 minutes later Belenenses scored only their 13th league goal of the season to earn a share of the spoils.
And it was Caeiro who proved to be the hero as he was presented with the simple task of slotting into an empty net following excellent work down the right from Geraldes.
