An insipid second half performance condemned Livi to a third-consecutive defeat as Dumbarton left West Lothian with all three points for the second successive visit.
The Lions had performed well in the first half and looked set to run riot, but fell away completely after the break as Dumbarton eventually eased to victory.
Livi took the game to Dumbarton from the outset and striker Marc McNulty was shown an early yellow card for apparent simulation on the edge of the visitors’ box, though the young frontman protested to referee Stephen Finnie that he had simply slipped on his own bootlace. Dumbarton then forced the first chance of the match as Mitch Megginson set up Jordan Kirkpatrick but he didn’t get the right contact on the ball and it slid wide of the post.
Livi then went up the other end and Andy Barrowman turned Aaron Barry but could only fire into the side netting. Livi were soon in front though thanks to a moment of sublime skill as Coll Donaldson dispossessed one-time Livi trialist Colin Nish and floated in a cross for McNulty who fired in a stunning first time volley which looped over Jamie Ewings and into the net.
Livi then came agonisingly close to a second as a strike rattled the crossbar after a corner from Martin Scott had caused chaos in the Sons’ box. The Lions kept up the pressure but couldn’t find the second goal and they were punished just before the break as Dumbarton drew level with a fine goal of their own. Andy Graham controlled the ball on the edge of the six yard box and teed up Megginson, who slammed a fine strike high into the net, leaving Kevin Walker with no chance. Shortly afterwards the Lions nearly had a second, as a strike rattled against Sons' crossbar from a corner.
The goal visibly lifted Dumbarton and they started the second half with renewed vigour, while Livi seemed to have lost their edge from the first half. The Sons should have led early in the second half as Kirkpatrick had a shot well saved by Walker before Nish blazed the rebound over. The lead soon came and it came in controversial circumstances as the visitors were awarded a penalty on 51 minutes when Connor MacDonald was adjudged to have fouled Paul McGinn. The contact appeared minimal and any contact there was looked outside the box, but the decision was made and Chris Turner stepped up and drilled in a low spot kick which squirmed under the body of the luckless Walker.
Livi tried to regain control but Dumbarton did a great job of shutting up shop before eventually killing the game off with a swift break on 74 minutes as Kirkpatrick switched the ball across to Mark Gilhaney who took one touch to run clear before selflessly squaring to Brian Prunty, scorer of a spectacular overhead kick on his last visit, who had a far simpler task to tap into the unguarded net.
Livi tried hard to get back into the game but offered little threat as Dumbarton saw the game out comfortably. The result saw Livi slip to eighth in the table, it had looked set to be worse until Cowdenbeath’s late collapse at home to Hamilton, five points ahead of bottom side Morton ahead of an increasingly crucial clash at Cappielow next week.
Livingston: 17 Walker, 7Jacobs, 19 Donaldson, 5 Fordyce, 3 Talbot, 6 Scott (Mullen 76), 8 O'Brien, 10 Scougall, 21 McDonald, 9 McNulty, 22 Barrowman (Wilkie 87)
Subs not used: 45 Rutherford, 31 Praprotnik, 1 Jamieson, 16 Beaumont, 20 Downie
Dumbarton: Ewings, McGinn, Graham, Barry, Linton, Murray (Agnew 55), Turner, Gilhaney (McDougall 79), Kirkpatrick, Megginson, Nish (Prunty 66)
Subs not used: Grindlay, Phinn, Smith
Referee: Stephen Finnie
Match report: Andrew Crawford