The Dons moved three points clear in second place with a fine 2-0 win against Motherwell.
Second half goals from Kari Arnason and Kenny McLean secured the victory for Aberdeen at a rainy Fir Park.
Conditions were far from ideal, but on a night when only the result mattered the Reds delivered with a professional display which nullified the Steelmen and moves them three points clear of the Gers in the battle for second with only six games remaining.
Dons boss Derek McInnes made one change from the side that beat St Johnstone 4-1 at Pittodrie on Saturday. Gary Mackay-Steven dropped to the bench with Arnason coming in to central defence and Anthony O’Connor being pushed into midfield.
The first opening of note was in the ninth minute when McLean fired wide from the left side of the area after neat link-up play with Stevie May and on the quarter hour skipper Graeme Shinnie fired well over from long range.
On 19 minutes there was a presentable chance for the men from the Granite City. Greg Stewart beat Stephen Hendrie wide on the right and weaved into the area.
He had May waiting for a cutback but went for the left-footed shot and lifted it over the bar.
Midway through the first period Ryan Christie freed Stewart on the left, his hanging cross to the back post was met by McLean but Hendrie blocked his header at close quarters.
Shortly after the half hour Hendrie made another vital intervention for Motherwell when he cleared Andy Considine’s low cross when Stewart was lurking ready to tap home.
Dons keeper Joe Lewis was called into action for the first time six minutes before half-time when he parried Ryan Bowman’s back post header from Richard Tait’s right-wing cross.
Chances continued to be at a premium as the interval drew closer with May curling a free-kick into the hands of home keeper Trevor Carson.
It was the Lanarkshire side who had the first chance of the second half when Tom Aldred headed Chris Cadden’s corner just wide in the 47th minute.
Motherwell started the second half with more intent, Curtis Main was stronger than Arnason and claimed a loose ball, but Lewis gathered his low strike from 20 yards at the second attempt.
Just after the hour May had a chance when Kipre dawdled and allowed him to pinch possession. May turned on the edge of the box but his shot was blocked by Aldred with the striker appealing for a penalty – but referee Don Robertson was unmoved.
But on 65 minutes it was Aberdeen who took the lead. After a good passing move ended in Motherwell conceding a corner on the right McLean swung it in with the left foot and Arnason powerfully headed home from eight yards.
And three minutes later it was 2-0 and game over.
The goal was created on the right flank with Logan finding Stewart on the right side of the area, he laid the ball off to McLean who curled an effort from 14 yards across Carson and into the far corner with his left foot.
There was a moment of panic for the Dons in the final five minutes when Shinnie and Arnason went for the same ball and allowed Motherwell to break upfield.
When the ball eventually landed at the feet of sub George Newell Considine blocked his effort.
However, after the collision Arnason required treatment and then had to be substituted, with Dominic Ball being sent on.
After that Aberdeen saw the game out comfortably – to the delight of the 962 Dons fans in the crowd of 4127 at Fir Park
Motherwell: Trevor Carson, Richard Tait, Cedric Kipre, Tom Aldred, Stephen Hendrie; Chris Cadden, Carl McHugh (George Newell 78), Allan Campbell (Gael Bigirimana 46), Elliot Frear (Ross MacLean 63); Curtis Main, Ryan Bowman.
Subs not used: Russell Griffiths, Liam Grimshaw, Barry Maguire, James Scott.
Aberdeen: Joe Lewis, Shay Logan, Kari Arnason (Dominic Ball 88), Scott McKenna, Andy Considine; Anthony O’Connor, Graeme Shinnie; Ryan Christie (Scott Wright 90+2), Kenny McLean, Greg Stewart (Adam Rooney 90+2), Stevie May.
Subs not used: Freddie Woodman, Mark Reynolds, Gary Mackay-Steven, Sam Cosgrove.