Match ends, Motherwell 3, St Mirren 0.
Henri Anier grabbed an impressive double as Motherwell ended St Mirren's run of four games without defeat at Fir Park.
The on-loan Viking Stavanger striker turned his markers dizzy before firing the opener from eight yards.
Lionel Ainsworth sped into the penalty box to slip the second past St Mijrren goalkeeper Marian Kello.
And Anier ensured a deserved victory with a fine half-volley finish from 12 yards.
The victory builds on the three points won by Stuart McCall's side away to Ross County last weekend and justifies his decision to name an unchanged starting line-up.
McCall spoke ahead of the game of his desire to extend the loan spells for Anier and Rotherham United winger Ainsworth.
And the 'Well boss will be doubling his efforts after they combined to ensure the Buddies followed six unbeaten games with successive defeats.
The pair combined straight from kick-off as Ainsworth's near-post cross was headed just wide by the Estonia striker.
St Mirren manager Danny Lennon had resisted the temptation to rest Paul McGowan after a no-doubt stressful week in which the midfielder pleaded guilty to two assaults on police officers.
With his bright orange boots, the 26-year-old showed no desire to hide from the public glare and his tenacious probings were asking questions of the home side, but they responded with a stout, if sometimes desperate, defence under trial.
However, it was Kello who was being given the stiffer test as he flew full length to turn wide a Simon Ramsden header and blocked an Ainsworth effort from point-blank range.
Lennon had brought Lee Mair into defence ahead of Marc McAusland, but the centre-half and captain Jim Goodwin were turned inside out by Anier as the striker fired the opening goal.
Apart from a slightly too high long-range effort from Gary Harkins, who had started ahead of John McGinn, the closest the visitors came to replying before the break was when on-loan Dundee goalkeeper Dan Twardzik flapped at the midfielder's corner before punching unconvincingly clear a second time.
Livewire Ainsworth was a constant threat down the Motherwell left and started and finished their second goal, slipping the ball past the advancing Kello after collecting a neat touch through from John Sutton.
Motherwell were again the more incisive after the break and Mair had to clear a goal-bound Sutton effort from in front of goal then Kello again blocked from Ainsworth.
St Mirren substitute McGinn stung Twardzik's palms with a rasping 16-yard drive, but any prospects of a fightback were ended with Anier's finish from an Iain Vigurs cross.
- 14LasleySubstituted forLawsonat 85'minutes
- 25AinsworthSubstituted forKerrat 77'minutes
- 24AnierSubstituted forMooreat 72'minutes
- 6GoodwinSubstituted forvan Zantenat 80'minutes
- 24NewtonBooked at 60minsSubstituted forMcGinnat 61'minutesBooked at 83mins
- 8HarkinsSubstituted forReillyat 77'minutes
- 2van Zanten
- William Collum
- Shots on Target
Keith Lasley (Motherwell) wins a free kick on the right wing.
Second Half ends, Motherwell 3, St Mirren 0.
Corner, Motherwell. Conceded by Sean Kelly.
Attempt missed. John Sutton (Motherwell) header from the centre of the box is close, but misses to the left.
Craig Moore (Motherwell) wins a free kick in the defensive half.
Foul by Lee Mair (St Mirren).
Substitution, Motherwell. Paul Lawson replaces Keith Lasley.
Corner, St Mirren. Conceded by Simon Ramsden.
John McGinn (St Mirren) is shown the yellow card.
Foul by John McGinn (St Mirren).
Substitution, St Mirren. David van Zanten replaces James Goodwin.
Substitution, Motherwell. Fraser Kerr replaces Lionel Ainsworth.
Substitution, St Mirren. Thomas Reilly replaces Gary Harkins.
Attempt missed. Steven Thompson (St Mirren) right footed shot from the centre of the box is close, but misses to the left.
Substitution, Motherwell. Craig Moore replaces Henri Anier.
Corner, Motherwell. Conceded by Lee Mair.
Foul by Stuart Carswell (Motherwell).
Paul McGowan (St Mirren) wins a free kick in the attacking half.
Foul by Simon Ramsden (Motherwell).