A debut goal from teenager Kyle Lander helped Livingston to an emphatic victory over Dumbarton.
Lander gave Livi the lead in the 30th minute when he slotted home from six yards following a cutback from Burton O'Brien.
Paul Watson doubled the visitors' lead, heading in from Liam Fox's outswinging corner just after half-time.
The Sons' threat was limited to set-pieces but they struggled to call goalkeeper Andrew McNeil into any meaningful action.
Livingston sealed victory 15 minutes from time when Danny Mullen slid the ball past Stephen Grindlay following an angled through ball from Kyle Jacobs.
The result leaves Livingston in fourth place, while Dumbarton remain four points clear of second-bottom Cowdenbeath with five matches to play.
Dumbarton: Grindlay, Asghar, Graham, Lithgow, Creaney (Horne 66), Gilhaney, Turner, Agnew, Lamont, Lister (Metcalf 79), McDougall (Prunty 52). Subs Not Used: Lumsden, Ronald.
Livingston: McNeil, Barr, Garcia Tena, Watson, McCann (Donaldson 81), Kyle Jacobs, O'Brien, Talbot, Booth (Downie 78), Lander (Mullen 72), Fox. Subs Not Used: Jamieson, Ross Gray.
Goals: Lander 32, Watson 47, Mullen 77.
Ref: William Collum