Goals from Anthony Murphy and Darragh Maguire were enough to give the Saints victory in this tense Dublin Derby.
A first half Anthony Murphy goal gave the Saints a one-nil half-time lead.
Superb work and a sublime pass from the returning Joseph Ndo put Murphy in the clear and he comfortably found the back of the Rovers net.
The Saints dominated the opening stages of the second half before Barry Ryan watched as a harshly awarded Rovers penalty came off the post and rebounded to safety.
The home teams dominance paid off as Darragh Maguire put the Saints two up, heading home a Keith Fahey corner.
Rovers reduced the deficit just two minutes later through Tadhg Purcell but the Saints held on to stay top of the league.