Pedro Santos came off the bench to net the decisive goal 16 minutes from time but not before their visitors passed up a glorious opportunity to take the lead.
A handball from Baiano three minutes into the second half saw Moreirense awarded a penalty but Matheus saved Andre Simoes' poorly struck spot-kick.
There was another near miss for Moreirense - who lie 10th in the table ahead of the weekend fixtures - Ramon Cardozo had an effort chalked off for offside four minutes before Santos headed home.
The result boosts the European ambitions of Sergio Conceicao’s team, who are guaranteed to finish the 19th matchweek in the top five.
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