ST MIRREN went down to their third league defeat in a row after a lacklustre performance against Craig Brown's rejuvenated Aberdeen side today.

Two second-half headers from Scott Vernon were enough to secure a deserved win for the on-form Dons, who looked the stronger side throughout as they made it four wins out of five.

The pre-match omens weren't good for Saints, who arrived today without a win at Pittodrie since March 1987 - and indeed, having only won five out of 42 meetings with the Dons since that day.

And they never really looked like changing that record during a grim 90 minutes for the Saints faithful, which will have given boss Danny Lennon plenty to ponder.

They managed to get through the game without registering a single shot on target, and one early Craig Dargo effort aside, posed almost no threat until the game was dead and buried late on.

The win for Aberdeen sees them move four points clear of a Saints side they trailed a couple of weeks ago, and leaves Lennon's men sinking further into a basement battle with Hamilton and Hibs.

Saints made three changes from the side which faced Peterhead in the cup last week, with injured duo Marc McAusland and Michael Higdon and the suspended Patrick Cregg dropping out.

In came Sean Lynch and David van Zanten, with the fit-again Lee Mair recalled to face the side he left in summer 2009. One-time Saints youngster David McNamee started for the home side.

The first threat came from Saints on 10 minutes. Paul McGowan's superb through ball released Dargo, who cut inside his man and fired a low shot inches past the post.

At the other end, Chris Maguire had a venomous effort deflected wide, then swung in the resulting corner himself for Andy Considine to power a header inches over.

But much of the opening period was scrappy and disjointed stuff, with the ball either in the air or bouncing around on the bumpy surface.

The Dons came close on 22 minutes when Ryan Jack robbed Jure Travner on the touchline and played the ball across goal, but Mair made a vital interception in the six-yard box.

Josh Magennis volleyed Maguire's cross just wide before Jack missed the target from a good position 15 yards out as the home side seized the upper hand.

Having survived this spell of pressure, Saints began to come into the game for the first time, but couldn't turn their possession into any threat to Jamie Langfield's goal.

Magennis was involved again ten minutes from the break when his superb run and shot was saved but not held by Paul Gallacher, forcing John Potter to hack the loose ball clear.

Just on half-time, the same player hooked a shot on the turn just past with Gallacher looking beaten, and the whistle arrived with the deadlock unbroken.