Perfect prep, tailored tactics, a rampant front three - how Dundee United saved their best to knock out Aberdeen

What a time for Dundee United to put in their best performance of the season.

Dundee United celebrate Marc McNulty's opener at Pittodrie.

With the objective of maintaining their Premiership status after promotion last season achieved a few weeks ago by, in the main, playing pragmatic football, Micky Mellon’s men decided to put on show at Pittodrie as they brushed aside Aberdeen 3-0 to reach the Scottish Cup semi-finals.

There have been some grumblings about United’s style under Mellon, who arrived this summer following Robbie Neilson’s defection to Hearts, but he and all involved at Tannadice can look forward to a date at Hampden in two weekends time for the first time since 2016, when they lost to Hibs on penalties in the Scottish Cup last four. At Pittodrie, they were superior to a desperately disappointing, fatigued Aberdeen in all departments and could easily have scored more goals.

Perfect preparations and tactics

Ryan Edwards rises highest to put United 2-0 up.

Mellon got his preparations spot on. He rested the core of his first team for last Wednesday’s fixture against Kilmarnock, which they lost 3-0. At the same time, Aberdeen’s players slugged it out with Celtic. All 11 of Glass’ starting XI here played in that match. United looked fresher and, with their three main forwards in Lawrence Shankland, Marc McNulty and Nicky Clark allowed to roam free and the intelligent Ian Harkes behind them, they ran the Dons off the sun-drenched pitch.

United clearly targeted Aberdeen down the flanks. The Dons were without experienced, recognised full-backs. Winger Jonny Hayes lined up at left-back, while 17-year-old Calvin Ramsay made only his fifth start at right-back. Both endured difficult afternoons, not helped by a distinct lack of protection from Florian Kamberi and Matty Kennedy ahead of them. United got a lot of joy in that area.

Keeping the door bolted has been an easier assignment for United this season, but reserve goalkeeper Deniz Mehmet deserves praise for making two important saves at the beginning of the match. Some expected Ross Doohan, signed on an emergency loan from Celtic on Saturday, to replace him. With regular No.1 Benjamin Siegrist sidelined by a wrist injury, this was an area of concern for United supporters. Mehmet assuaged any fears.

Broken Glass

United manager Micky Mellon congratulates McNulty on his two goals.

As good as United were, Aberdeen’s performance disappointed manager Glass. In only his third match in charge of this team, aside from the opening ten minutes, they were second best, jaded by three games in a week. Too many of his players just did not hit the required standard. They missed the leadership of captain and goalkeeper Joe Lewis, only able to make the bench after a rib injury, and the drive and energy of Ross McCrorie. Dean Campbell and Lewis Ferguson lost the midfield battle to Calum Butcher and Jeando Fuchs. Callum Hendry spurned two presentable early chances, Kamberi was ineffective and Niall McGinn’s final ball let him down too often.

Glass is still getting to know his team and had limited options within the group. They did not play like the Aberdeen we have watched for the last eight years under Derek McInnes. In fact, they were worse, more open and less spirited. The 44-year-old will need time, patience and – most importantly – his own players to turn this tanker around. Barring an incredible turnaround, they are booked for fourth place in the Premiership, seemingly too far behind Hibs in third and nine points clear of fifth-placed Livingston with three league matches remaining. At the very least, Glass will look for a reaction in that trio of matches.

Had Hendry not scooped the ball over the bar on seven minutes, nor watch his close-range effort from a rebound whack Mehmet on the torso moments later, this match might have followed a different trajectory. As it was, those two chances were Aberdeen’s best as United grabbed control of proceedings and never let go.

How United ran riot

Aberdeen manager Stephen Glass can't hide his dejection.

Their opening strike came on 18 minutes. Shankland was at the heart of it down the left, taking the ball in and shuttling out to McNulty, who was free on the right. The on-loan Reading forward took a touch to steady himself before shooting across Aberdeen keeper Gary Woods and into the bottom corner.

One-nil was so nearly 2-0 a minute later. Once again McNulty was found free on the right and his pass across goal was just out of the reach of Harkes. Had connection been made, it would have been a two-goal advantage.

United were playing with a swagger. After some neat passing, centre-half Reynolds strolled forward before picking out the advancing Fuchs with a curled pass. The Cameroonian’s powerful effort was straight at Woods, though.

Clark was next to go close, with a shot from outside the box that clipped the post. Aberdeen, at this point horribly passive in midfield and creaky at the back, had fallen out of the game.

United deserved a second goal for the way that they had totally bossed the first period and it arrived on 37 minutes. For all their pretty passing, this goal was about simplicity. Clark swung in an inviting free-kick and Ryan Edwards rose highest in the penalty box and planted a header into the bottom corner.

Aberdeen were more purposeful at the start of the second half, but on 54 minutes, they effectively tucked the match up and wished it goodnight. McNulty played a neat one-two with Harkes, spun into the space behind the Aberdeen defence and coolly slipped the ball under Woods for his second of the game.

Aberdeen huffed and puffed thereafter but United stood tall, defending well. Now in four matches, they’ve kept the Dons out, a clean-sheet quadruple. Mellon was a picture of contentment, Glass less so. His team’s season hangs by a thread now. Dundee United can look forward to Hampden.

Aberdeen: Woods; Ramsay, Hoban, Considine, Hayes; Kennedy, Ferguson, Campbell (Ross 62), Kamberi; McGinn (McGeouch 62), Hendry (Ruth 77).

Dundee United: Mehmet; Smith, Edwards, Reynolds, Robson; Butcher (Pawlett 83); Fuchs, Harkes; McNulty, Clark (Bolton 88); Shankland (Appere 88).

Get a year of unlimited access to all The Scotsman's sport coverage without the need for a full subscription. Expert analysis of the biggest games, exclusive interviews, live blogs, transfer news and 70 per cent fewer ads on Scotsman.com - all for less than £1 a week. Subscribe to us today