Match ends, Livingston 2, St. Mirren 1.
Livingston 2-1 St Mirren: Gary Holt's side move within four points of third
Livingston are just four points off third place in the Scottish Premiership after picking up a sixth home league win in a row by beating St Mirren.
Steven Lawless scored from the penalty spot for Gary Holt's side, after Conor McCarthy tripped Lyndon Dykes in the box.
Then the Australian struck again moments after the break when he latched on to a long ball to tap home a second.
The guests pulled one back through a tidy finish from Jonathan Obika.
However, that wasn't enough to stop St Mirren's winless run from extending to six matches as Jim Goodwin's side remain just four points off bottom spot.
Efficient Livingston keep marching on
With just two home league defeats this season, the onus was on Livingston against their relegation-threatened visitors and they took the initiative against a side who had gone unbeaten in four and held Aberdeen, Hibernian and Motherwell in that time.
Jon Guthrie's close-range header was blocked three minutes in, and a speculative volley at the back post went flying over the bar 10 minutes after that. An Aaron Taylor-Sinclair free-kick then came even closer, a late dive from Vaclav Hladky stopping it finding the bottom right-hand corner.
Jim Goodwin's side battled, but their chances were few and far between and they were chasing the game from early on after slipping behind.
McCarthy and Dykes pursued a long ball over the top, with the latter tumbling under pressure and inviting referee David Munro to award a penalty. Steven Lawless then stepped up to convert.
Livingston probably deserved more than a one-goal lead at the break, and Dykes burnished the advantage just after the interval when substitute Keaghan Jacobs played the Australian through to slip the ball past Hladky.
After seemingly putting the game beyond doubt, Holt's side then conceded their first home goal in 540 minutes of league football when Cameron MacPherson played through Obika for his eighth goal of the season.
St Mirren should have pushed on for an equaliser but Livingston the regained control. Scott Robinson was denied by Hladky, then Dykes got on the end of a, only to see his header hit the woodwork.
The visitors pushed for a late equaliser, as long-range shots from Sam Foley and MacPherson stung the gloves of a Robby McCrorie, but never looked like causing an upset.
In the end, it was another efficient home win for a Livingston side that may now have ambitions of qualifying for Europe, even if they'd never dare admit it.
St Mirren, with just one win in 13 away games, continue to wrestle with relegation.
Man of the match - Lyndon Dykes
BBC Scotland's Kenny Macintyre at the Tony Macaroni Arena
The mark of a top striker is when you see him racing through from a good distance out that you have no doubt the ball will hit the net. And so it was just 20 seconds into the second half.
From that sublime finish, to the other side of the game. With the match deadlocked at 0-0, Dykes burst into the area and looked to be going nowhere, but drew McCarthy into a challenge: penalty awarded, Livingston in front.
The home fans should enjoy him while he's here - he's surely destined for bigger things come the summer.
'Last year we may have drawn or lost that' - reaction
Livingston manager Gary Holt: "It wasn't pretty. I don't think we did the basics well enough in the second half. Our game management wasn't there. It was scrappy.
"We are a wee bit more experienced and they saw the game out. Last year we might have drawn that 2-2 or lost 3-2, so I'll give them credit for that."
St Mirren manager Jim Goodwin: "Both goals are a shambles. We were far too high on both occasions. To start the second half in that manner is incredible. We were all over the place. Far too high, too much space, the shape of the defensive line - it's just everything that we haven't been of late.
"To go two goals down against at team that defends as well as Livingston was always going to be a massive uphill task."
- 21McMillanSubstituted forLawsonat 80'minutes
- 6BartleySubstituted forJacobsat 45'minutes
- 17RobinsonSubstituted forMengaat 73'minutes
- 19MoriasBooked at 24minsSubstituted forMcAllisterat 74'minutes
- 11DurmusSubstituted forMullenat 84'minutes
- 28JakubiakSubstituted forMcGrathat 79'minutes
- David Munro
- Shots on Target
Second Half ends, Livingston 2, St. Mirren 1.
Corner, St. Mirren. Conceded by Robby McCrorie.
Attempt saved. Cameron MacPherson (St. Mirren) right footed shot from outside the box is saved in the top left corner.
Attempt missed. Jonathan Obika (St. Mirren) header from the centre of the box is just a bit too high.
Dolly Menga (Livingston) wins a free kick on the left wing.
Foul by Calum Waters (St. Mirren).
Corner, St. Mirren. Conceded by Lyndon Dykes.
Attempt blocked. Jonathan Obika (St. Mirren) header from the centre of the box is blocked.
Foul by Keaghan Jacobs (Livingston).
Daniel Mullen (St. Mirren) wins a free kick on the right wing.
Hand ball by Kyle McAllister (St. Mirren).
Substitution, St. Mirren. Daniel Mullen replaces Ilkay Durmus.
Foul by Craig Sibbald (Livingston).
Cameron MacPherson (St. Mirren) wins a free kick in the defensive half.
Attempt missed. Cameron MacPherson (St. Mirren) right footed shot from a difficult angle and long range on the left misses to the right from a direct free kick.
Foul by Steve Tevi Lawson (Livingston).
Jamie McGrath (St. Mirren) wins a free kick in the defensive half.
Substitution, Livingston. Steve Tevi Lawson replaces Jack McMillan.
Corner, Livingston. Conceded by Sam Foley.
Substitution, St. Mirren. Jamie McGrath replaces Alex Jakubiak.
Corner, St. Mirren. Conceded by Ciaron Brown.
Attempt saved. Sam Foley (St. Mirren) left footed shot from outside the box is saved in the centre of the goal.
Foul by Dolly Menga (Livingston).
Calum Waters (St. Mirren) wins a free kick in the attacking half.
Substitution, St. Mirren. Kyle McAllister replaces Junior Morias.
Substitution, Livingston. Dolly Menga replaces Scott Robinson.
Attempt missed. Steven Lawless (Livingston) left footed shot from outside the box is high and wide to the left.
Scott Pittman (Livingston) wins a free kick in the defensive half.
Foul by Cameron MacPherson (St. Mirren).
Foul by Jon Guthrie (Livingston).
Jonathan Obika (St. Mirren) wins a free kick in the defensive half.
Attempt missed. Lyndon Dykes (Livingston) header from the centre of the box is close, but misses to the left following a corner.
Corner, Livingston. Conceded by Conor McCarthy.
Attempt saved. Scott Robinson (Livingston) left footed shot from the centre of the box is saved in the centre of the goal.
Foul by Scott Pittman (Livingston).
Sam Foley (St. Mirren) wins a free kick in the attacking half.
Corner, Livingston. Conceded by Calum Waters.
Foul by Scott Pittman (Livingston).
Akin Famewo (St. Mirren) wins a free kick in the attacking half.