Livingston leapfrogged Hamilton to move in to third place in the First Division with a hard-fought win in West Lothian.
Rory Boulding's great cross found Marc McNulty who headed the 52nd-minute winner into the bottom corner.
Craig Barr almost doubled the lead but his header went narrowly wide before Hamilton pushed hard for an equaliser.
A shot from James Chambers was well saved by Andy McNeil and the same player had a shot deflected wide by Kenny Deuchar with six minutes to go.
Livingston: McNeil, Kyle Jacobs, Craig Barr, Watson, Talbot, Keaghan Jacobs (Scougall 46), Fotheringham, Robert Barr, Boulding (Cummings 87), Deuchar, McNulty (Russle 90). Subs Not Used: Jamieson, Naples.
Goals: McNulty 52.
Hamilton: Hutton, Mensing, Canning, McLaughlin, McAlister, Imrie, Fraser (Chambers 54), McBride (Kirkpatrick 79), Anderson, Paterson, Spence (Hendrie 54). Subs Not Used: Crawford.
Booked: Mensing, McLaughlin.
Referee: John McKendrick