A string of dodgy decisions from whistler Paul Robertson aided a Dumbarton victory.
The Sons were lucky to have only Mark Gilhaney sent off in a bad-tempered encounter where scorer Bryan Prunty and goalie Jamie Ewings should have followed him off the park.
Sons hitman Prunty fired home a sensational overhead kick on four minutes to open the scoring.
He chested into the air a cross from Paul McGinn before bicycle-kicking home.
Stand-in striker Jordan Morton took full advantage of his start ahead of crocked Marc McNulty when he tapped home from an Iain Russell cross to level soon after.
But Dumbarton were back ahead moments later when Livi goalie Andy McNeil - under pressure from Alan Lithgow - spilled the ball into the path of Andy Graham who netted from close range.
The Lions began to put Dumbarton under considerable pressure with Sons shot-stopper Ewings forced to pull off a string of top-class saves as Livi looked to get back into the game.
Tony Andreu was denied when his bullet header was tipped onto the post, before Ewings once again kept Livi out with a fine save to deny Kyle Jacobs whose header from a Morton free-kick was goal-bound.
And Ewings was the hero once more moments later with a double-save from an Andreu header and Russell follow-up.
But with Livingston now in complete control, it was only a matter of time before they pulled level. Russell burst clear of the Dumbarton defence and was scythed down by Ewings handing Livi a clear penalty.
Russell netted from the spot to level the match at the break.
Dumbarton grabbed the lead back for a third and final time when Agnew fired home from the spot after Prunty was felled in the box by Kyle Jacobs.
Prunty miraculously escaped a red card when he hacked down Jesus Garcia Tena moments after being infuriated by a tackle the Spaniard had made on Jim Lister.
Lions’ sub Danny Mullen rounded Ewings late on but was denied by the post as Dumbarton held on.
