Jesualdo Ferreira's men went into the clash at the Estadio Axa having lost five in a row while scoring just once, but they flew out of the traps and were 2-0 up inside 13 minutes thanks to Aderllan Santos and Rafa Silva.
Celestino pulled one back for Olhanense from the penalty spot 11 minutes into the second half, but Eder then struck with 20 minutes to go for the hosts before Felipe Pardo sealed Braga's win in injury time.
Santos opened the scoring with a smart finish with just seven minutes on the clock, before Silva fired home his first of the season just six minutes later.
Olhanense - who themselves went into the game without a win in four - responded well after the break, though, and were given a route back into the match when Celestino netted from 12 yards.
However, Eder calmed the home fans' nerve with a close-range finish on 69 minuted, before substitute Pardo - who had been on the pitch less than a minute - beat Vid Belec to add gloss to the scoreline late on.
