The result means Pacos, who are on 54 points and have one match to play, are certain to finish above fourth-placed Braga who are five points behind after losing 3-1 at home to Nacional Madeira.
It is a major feat for Pacos who are based in a tiny town north of Porto.
They took the lead through midfielder Manuel Jose following a flowing counter attack in the second half before Academica levelled from the penalty spot with 20 minutes to go.
Pacos, who are nicknamed 'The Beavers', have a small stadium with a capacity of just over 5,000.
Club president Carlos Barbosa said he was living the dream.
"This is a breath of fresh air for a team that goes through the difficulties that we do," he told Portuguese television.
"It will be a great cash inflow to improve our stadium which we will try and have ready in time for the Champions League," added Barbosa of a club that has an annual budget of 2.5 million euros.
"We dream of hosting Real Madrid or Barcelona."