Johnny Russell scored a second-half hat-trick as Dundee United cruised into the fifth round of the Scottish Cup at the expense of Airdrie United.
John Rankin fired the 2010 winners ahead, with Scott Robertson adding a cool side-foot finish.
Russell lashed in a powerful strike 17 minutes after the interval and then headed home Paul Dixon's cross.
Gary Mackay-Steven powered in a shot before Russell struck again, with Ryan Donnelly replying twice late on.
The hosts had defeated Gala Fairydean 11-0 in the previous round and their bright start suggested they were in the mood to avenge a 2-0 defeat to United in the Scottish Communities League Cup earlier this season.
Jamie Stevenson saw his deflected effort from the edge of the area fly just over and from the resultant corner the Airdrie midfielder came close again, this time seeing his shot come back off the crossbar.
However, the Second Division side were soon undone on when former Diamond Mackay-Steven found Rankin bursting into the box and he fired powerfully past Connor Fairley.
Willie McLaren passed up a great chance to equalise when he volleyed straight at Dusan Pernis midway through the half and the Slovak was again on hand to deny Stevenson as Airdrie pressed forward.
It was the visitors though who were demonstrating the greater quality in the final third and in particular the combination of Dixon and Mackay-Steven down the left.
Dixon's low cross just evaded the on-rushing Russell and Jon Daly four minutes before the break but Airdrie didn't heed the warning and the second goal arrived just a minute later.
Mackay-Steven's excellent cut-back found Russell who laid the ball into Robertson's path and the midfielder expertly guided the ball into the top corner.
The second half followed a similar pattern as after a promising start to the half Airdrie conceded again. This time Russell found acres of room inside the area to control Willo Flood's cross before crashing an excellent finish into the roof of the net.
The gulf in quality was now starting to tell and the Scottish Premier League side added another two quickfire goals as Russell headed home another excellent Dixon cross before Mackay-Steven got the goal his performance deserved with an accurate shot across Fairley.
Russell completed his hat-trick as he slotted home the rebound after Fairley had blocked his first effort.
There was time for Airdrie to score twice as Donnelly first rounded Pernis and slotted into the empty net before heading in at the far post with the last touch of the game.
Live Text Commentary
Full Time The referee blows his whistle to end the game.90:00 +1:26
The assist for the goal came from William McLaren.90:00 +1:26 Goal scored
Goal! - Ryan Donnelly - Airdrie U 2 - 6 Dundee U Ryan Donnelly grabs a goal from close range low into the middle of the goal. Airdrie Utd 2-6 Dundee Utd.90:00 +1:00
Corner taken left-footed by William McLaren.84:41
Assist by William McLaren.84:41 Goal scored
Goal! - Ryan Donnelly - Airdrie U 1 - 6 Dundee U Ryan Donnelly finds the back of the net with a goal from close in low into the middle of the goal. Airdrie Utd 1-6 Dundee Utd.83:28
Nathan Blockley has an effort at goal from 20 yards.83:28 Substitution
Substitution (Airdrie Utd) makes a substitution, with Rhys Devlin coming on for Jamie Stevenson.83:28
Lauri Dalla Valle provided the assist for the goal.83:28 Goal scored
Goal! - Johnny Russell - Airdrie U 0 - 6 Dundee U Johnny Russell finds the back of the net with a goal from close in low into the middle of the goal. Airdrie Utd 0-6 Dundee Utd.82:37
William McLaren has an effort at goal from deep inside the area missing to the right of the target.81:13
Corner taken left-footed by Barry Douglas from the left by-line, clearance made by Nathan Blockley.79:10
The assistant referee flags for offside against Johnny Russell. Paul Lovering takes the indirect free kick.78:36
Ryan Donnelly is ruled offside. Free kick taken by Garry Kenneth.74:21
Free kick taken by Willo Flood.74:21 Booking
Booking Paul Lovering shown a yellow card.74:12
Free kick awarded for a foul by Paul Lovering on Scott Robertson.70:30
Johnny Russell is flagged offside by the assistant referee. Connor Fairley restarts play with the free kick.70:30 Substitution
Substitution Barry Douglas joins the action as a substitute, replacing John Rankin.70:30
Assist by Scott Robertson.
Goal! - Gary Mackay-Steven - Airdrie U 0 - 5 Dundee U Gary Mackay-Steven gets on the score sheet with a goal from deep inside the penalty box to the bottom left corner of the goal. Airdrie Utd 0-5 Dundee Utd.67:19
The assist for the goal came from Garry Kenneth. The assistant referee signals for offside against Johnny Russell. Connor Fairley restarts play with the free kick.67:19 Goal scored
Goal! - Johnny Russell - Airdrie U 0 - 4 Dundee U Johnny Russell finds the net with a headed goal from close range. Airdrie Utd 0-4 Dundee Utd.65:02 Substitution
Substitution Lauri Dalla Valle joins the action as a substitute, replacing Jon Daly.65:02 Substitution
Substitution Phillip Johnston replaces Sean Lynch.61:21
Assist on the goal came from Jon Daly.61:21 Goal scored
Goal! - Johnny Russell - Airdrie U 0 - 3 Dundee U A goal is scored by Johnny Russell from deep inside the penalty box to the top left corner of the goal. Airdrie Utd 0-3 Dundee Utd.58:09
Inswinging corner taken by Jamie Stevenson, Garry Kenneth makes a clearance. Garry Kenneth gives away a free kick for an unfair challenge on Derek Holmes. Jamie Stevenson restarts play with the free kick. Ryan Donnelly is adjudged to have handled the ball. Dusan Pernis restarts play with the free kick.57:43
The assistant referee flags for offside against Johnny Russell. Direct free kick taken by Kieron Stallard.56:35 Substitution
Substitution Richie Ryan replaces Stuart Armstrong.55:40
Free kick awarded for a foul by John Rankin on Sean Lynch. William McLaren restarts play with the free kick.54:49
Shot from 18 yards from William McLaren. Blocked by Dusan Pernis.54:25
The referee gives a free kick against Stuart Armstrong for handball. David Lilley restarts play with the free kick.53:27
Effort from inside the area by Stuart Armstrong misses to the right of the goal.51:20
Foul by Sean Lynch on John Rankin, free kick awarded. Shot on goal comes in from Garry Kenneth from the free kick, Connor Fairley gets a block in.49:22
Corner taken left-footed by Gary Mackay-Steven. Gary Mackay-Steven takes the outswinging corner, Paul Lovering makes a clearance.47:05
Effort from outside the penalty area by Ryan Donnelly goes wide left of the target.46:42
Handball by Gary Mackay-Steven. Connor Fairley takes the direct free kick.45:54
Nathan Blockley concedes a free kick for a foul on Johnny Russell. John Rankin restarts play with the free kick.45:01
The match restarts for the second half.45:00 +1:20 Half time
Half Time The referee blows for half time.44:56
Inswinging corner taken by Jamie Stevenson from the left by-line, Jon Daly manages to make a clearance. Outswinging corner taken right-footed by Jamie Stevenson. Inswinging corner taken from the right by-line by Jamie Stevenson.42:07
Assist on the goal came from Johnny Russell.42:07 Goal scored
Goal! - Scott Robertson - Airdrie U 0 - 2 Dundee U Scott Robertson finds the back of the net with a goal from deep inside the penalty box to the top right corner of the goal. Airdrie Utd 0-2 Dundee Utd.41:16
Effort from 12 yards by Paul Dixon.40:10
Effort on goal by Jamie Stevenson from 6 yards. Dusan Pernis gets a block in.39:26
Free kick awarded for an unfair challenge on Nathan Blockley by John Rankin. David Lilley takes the direct free kick.37:32
Jamie Stevenson takes the free kick.37:32 Booking
Booking Garry Kenneth is shown a yellow card.37:21
The referee gives a free kick against Garry Kenneth for handball.35:01 Booking
Booking Booking for Jamie Stevenson.34:26
Free kick awarded for a foul by Garry Kenneth on Jamie Stevenson. Free kick taken by Jamie Stevenson.33:41
Sean Lynch has a shot on goal from long range that goes wide left.32:06
Free kick awarded for an unfair challenge on Scott Robertson by David Lilley. Dusan Pernis takes the indirect free kick.31:26
Corner taken right-footed by Jamie Stevenson.30:13 Substitution
Substitution Derek Holmes comes on in place of Kevin Green.23:52
Johnny Russell concedes a free kick for a foul on Kieron Stallard. Direct free kick taken by Connor Fairley.22:38
Johnny Russell concedes a free kick for a foul on Paul Lovering. Paul Lovering takes the free kick.22:14
Shot from 18 yards by William McLaren. Blocked by Dusan Pernis.21:11
David Lilley gives away a free kick for an unfair challenge on John Rankin. Direct free kick taken by John Rankin.18:58
The assistant referee signals for offside against Gary Mackay-Steven. Connor Fairley restarts play with the free kick.18:09
Gary Mackay-Steven fouled by Jamie Stevenson, the ref awards a free kick. Direct free kick taken by Dusan Pernis.16:06
Assist on the goal came from Gary Mackay-Steven.16:06 Goal scored
Goal! - John Rankin - Airdrie U 0 - 1 Dundee U John Rankin finds the net with a goal from inside the six-yard box to the bottom right corner of the goal. Airdrie Utd 0-1 Dundee Utd.14:27
Johnny Russell takes the chance to get an effort at goal.12:42
Free kick awarded for an unfair challenge on Willo Flood by Nathan Blockley. Willo Flood takes the free kick.11:58
Jamie Stevenson fouled by John Rankin, the ref awards a free kick. Paul Lovering takes the free kick.10:13
Jamie Stevenson has an effort at goal from 20 yards. Inswinging corner taken from the right by-line by William McLaren. Corner taken by William McLaren from the right by-line, clearance by Garry Kenneth.7:55
Garry Kenneth gives away a free kick for an unfair challenge on Sean Lynch. David Lilley takes the free kick.3:22
The official flags Jon Daly offside. Free kick taken by Connor Fairley.2:22
Corner taken by William McLaren, clearance by Garry Kenneth.0:54
Shot by William McLaren from 12 yards. Blocked by Dusan Pernis.0:00
The ref blows the whistle to begin the match.
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