Rui Vitoria's men had to come from behind to clinch the points after Sergio Oliveira put the hosts ahead in the 10th minute.
The 21-year-old fired home from outside the box to pick up his first league goal for the team, and heap the pressure on their visitors early on.
Pacos were unable to sustain the pressure though, and it was just minutes before half-time that Vitoria managed to equalise with Leonel Olimpio confidently sending a penalty down the middle to enter the half-team break on level terms.
They then also came out the better of the sides in the second half and it was not long before Marcos Matias was able to go round Antonio Filipe to coolly slot home.
There was further misery for the hosts shortly before the final whistle too, with Tomane scrambling past Filipe to poke the ball in the back of the net and seal the three points.
The result sees Pacos, who finished third last season, continue to languish at the bottom of the league with eight games played, and they will hope to get back to winning ways when they face Arouca on Sunday.
