It was a thoroughly merited victory and one which moves them three points clear of Graeme Murty’s faltering Rangers side with only six league games remaining.

That would have been satisfying enough for manager Derek McInnes, pictured, but there was the added bonus of denting the confidence of last night’s opponents, whom they meet again at the national stadium in the semi-final of the Scottish Cup a week on Saturday.

Surviving a bruising encounter on a treacherous surface without adding to their injury list would have added to the feelgood factor as Aberdeen made the long journey back north to prepare for Saturday’s meeting with Hearts at Tynecastle.

Aberdeen midfielder Kenny McLean celebrates his goal as Aberdeen eased to a 2-0 victory at Fir Park. Picture: Rob Casey

It was a professional display from McInnes’ side, who appear to have regained their best form at just the right time.

The Dons were the first to threaten when Graeme Shinnie and Stevie May combined to release Kenny McLean but the midfielder’s finish from 15 yards lacked composure and accuracy. Greg Stewart did rather better in the 19th minute, engineering a shooting opportunity but his effort was slightly too high.

The traffic was all one way at this stage and Richard Tait took one for the team when he bravely blocked a netbound shot from May.

However, while the visitors dominated possession, they could not turn it into something more palpable and, on a greasy surface, they were just as vulnerable as their opponents to a costly defensive mistake.

It took the home side until seven minutes from the interval to threaten Joe Lewis’s goal and, when Tait picked out Ryan Bowman with a deep cross from the right touchline, the goalkeeper threw out his left hand to palm away the striker’s header at the far post, but Motherwell would undoubtedly have been happier with the first-half scoreline.

They lost midfielder Allan Campbell to injury but, galvanised by a pep talk from manager Steve Robinson, they came flying out of the traps at the restart and Tom Aldred wasn’t far away with a header.

Curtis Main had been both well policed and starved of ammunition during the opening period but he outmuscled Kari Arnason at a cross, reacted the quickest to the loose ball and Lewis could only parry his bouncing bomb of a shot from 25  yards.

For the first time in the contest, the hosts enjoyed the upper hand, although their cause was not helped by referee Don Robertson’s lenient approach to some robust challenges from Aberdeen’s back line. Motherwell’s willingness to surge forward meant that there were spaces for Aberdeen to exploit and, when Cedric Kipre lost his footing, it required a smothering block from Aldred to deny May.

Even so, it was against the run of play when they broke the deadlock midway through the second half and there will be questions asked about the home side’s defending. Icelandic veteran Arnason was left with a free header at a McLean corner and Trevor Carson could have done more to keep the defender’s header out.

There were no caveats attached to their second goal, however; it was superb. McLean took a short corner to Stewart, accepted the return pass and then curled a left-foot shot low inside Carson’s right-hand post from the far corner of the 18-yard box.

Surprisingly for such a physical encounter, the first caution didn’t arrive until 11 minutes from the end, with Tait seeing yellow for a foul on May.

By then Motherwell were utterly deflated and they will require a great deal of lifting for their return to Hampden.

Their prospects of claiming a top-six finish have now gone, but it was the nine-game winless run in November and December (a hangover from their BetFred Cup final defeat to Celtic) which has denied that achievement, not this defeat.

Motherwell 0-2 Aberdeen: Dons take control of second place