Mark Leech's goal for St Pat's earned Jeff Kenna's side a second win of the season at The Showgrounds.
Leech struck the only goal of the game in the 31st minute, after Rovers keeper Richard Brush watched his fine save from Jason Gavin's close-range effort rebound perfectly for the former Derry City striker to finish.
It was the Saints' second 1-0 win in succession and moves them up to fourth in the table, while Rovers are still looking for their first win of the season.
Pat's manager Kenna kept faith with most of the team that defeated Cork last time out, although Gary Dempsey returned from suspension in place of the banned Damien Lynch, while Gareth O'Connor also returned to the starting 11.
Paul Cook made two changes to the Sligo team beaten by Shamrock Rovers in Tallaght, with Alan Keane returning from suspension and Stephen Parkhouse earning his first competitive start.
Sligo native Alan Cawley, a target for Rovers in the close season, saw an early free-kick from the edge of the area fly just wide of the post, before striker Leech forced Rovers keeper Brush into an early save with a dipping shot.
The home side settled into the game after this, and Owen Morrison skilfully made space at the edge of the area before firing a right-foot shot straight at Gary Rogers.
The Pat's keeper made an even better save to deny Brian Cash on 21 minutes, after the ball had broken invitingly to the winger close to goal.
Ten minutes later, Brush pulled off an equally sharp save to deny Gavin at the other end, but Leech was perfectly placed to smash the rebound to the net.
The closest Rovers came to finding an equaliser came in the last minute of the half, when Raffaele Cretaro dribbled into the area, but saw his shot smothered by Rogers.
Pat's could have doubled their lead ten minutes into the second half, when David Partridge met Leech's cross, but the centre-back directed his header wide.
Mark Quigley marked his return to action following injury as a 70th minute replacement for goalscorer Moran, but he failed to spark an uneventful second half to life.
That mattered little to Pat's though, as they moved to just a point behind the early leaders.