Motherwell made their first Scottish Cup final for 20 years after a first-half demolition of St Johnstone.
Stephen Craigan nodded the Steelmen in front after just five minutes when Saints goalkeeper Peter Enckelman failed to deal with a corner.
Jamie Murphy doubled their lead soon after with a fine run and low shot.
John Sutton effectively killed off the game before the break with a superb 35-yard volley, with Murray Davidson hitting the bar for Saints late on.
Motherwell will now have the chance to win their third Scottish Cup in their seventh final appearance on 21 May, when they'll face the winner of Sunday's semi-final between Aberdeen and Celtic.
McCall delight at Cup final place
No St Johnstone player had scored against SPL opposition since 2 February, but they almost changed that statistic within 90 seconds at the national stadium.
Danny Grainger whipped free-kick into the Motherwell box, which Danny Invincibile flicked on from the penalty spot, and goalkeeper Darren Randolph had to dive acrobatically to tip the ball over the bar.
But Saints' good start was undone minutes later, when Randolph's opposite number Enckelman was badly at fault to allow Motherwell to take the lead.
The Finn completely missed an attempt to punch the ball away at a corner, and Steelmen captain Craigan gratefully nodded in from close range.
Soon after Well doubled their lead with the help of some fortune in the build-up when they retained possession in midfield when a slack pass bounced off referee Iain Brines.
Jamie Murphy received the ball, ran with it across the box while Saints defence backed off, and then he fired a low shot across Enckelman inside the far post.
Davidson almost replied immediately from a bizarre ricochet at a Craigan clearance, and the Saints midfielder watched another shot from 25 yards sail just over.
But those were interludes in what was fast becoming a very one-sided affair.
Motherwell should have made it 3-0 after half-an-hour, when Keith Lasley jinked past Dave Mackay before he shot wide from a good position in the box.
Then Murphy almost scored after another solo run from midfield, but this time his shot went the wrong side of the post by an inch.
Well did take a third goal before the break, and they did so in spectacular fashion.
Randolph pumped the ball long towards his forwards and Francis Jeffers nodded it back towards his advancing partner Sutton.
The Englishman kept up his record of scoring in every round of this year's cup, smashing a fierce dipping volley over Enckelman from fully 35 yards - although again the Saints number one's positioning was suspect.
St Johnstone began the second period with more urgency and Davidson was frustrated by Randolph as the Well goalkeeper tipped over his fine strike from 25 yards.
Grainger also had a free-kick on target, although it did not trouble Randolph, who held it easily.
But Motherwell had done the damage in the first 45 minutes and Saints' afternoon was summed up when Davidson watched a late header crash back off the bar with Randolph for once beaten.
Live text and stats
Saturday, 16 April 2011
07 Humphrey (Jones 78)
08 Jennings yellow card (Ross 75)
24 Jeffers (McHugh 66)
06 Duberry yellow card
10 Craig yellow card
14 Moon (May 66)
21 Samuel (Robertson 46 yellow card)
Ref: BrinesAtt: 11,920
Attempts on target
Attempts off target
90:00+3:04 The referee blows for the end of the match.
90:00+2:20 Jordan Robertson concedes a free kick for a foul on Steve Jones. Tom Hateley takes the direct free kick.
90:00+2:01 Short corner worked by Tom Hateley.
89:56 Headed effort from inside the area by Liam Craig misses to the right of the target.
88:30 Murray Davidson takes a shot. Shaun Hutchinson gets a block in.
87:04 Free kick awarded for a foul by Tom Hateley on Jordan Robertson. Liam Craig restarts play with the free kick.
84:43 The official flags Jordan Robertson offside. Darren Randolph takes the indirect free kick.
82:13 Unfair challenge on Michael Duberry by Steve Jones results in a free kick. Peter Enckelman restarts play with the free kick.
81:08 Free kick taken by Darren Randolph.
81:08 Booking Booking for Liam Craig.
80:44 Foul by Liam Craig on Jamie Murphy, free kick awarded.
80:04 Outswinging corner taken left-footed by Murray Davidson from the left by-line, Murray Davidson takes a shot.
79:21 Unfair challenge on Stephen Craigan by Jordan Robertson results in a free kick. Free kick taken by Darren Randolph.
77:54 Corner taken left-footed by Stevie Hammell, save by Peter Enckelman.
77:54 Substitution Steve Jones is brought on as a substitute for Chris Humphrey.
75:49 Foul by Maurice Ross on Liam Craig, free kick awarded. Jordan Robertson shoots direct from the free kick.
74:25 David MacKay takes the direct free kick.
74:25 Substitution Maurice Ross is brought on as a substitute for Steve Jennings.
74:25 Jordan Robertson fouled by Stevie Hammell, the ref awards a free kick.
68:59 Jordan Robertson gives away a free kick for an unfair challenge on Tom Hateley. Free kick taken by Darren Randolph.
68:01 Corner taken left-footed by Stevie Hammell, free kick awarded for a foul by Shaun Hutchinson on David MacKay. Peter Enckelman
restarts play with the free kick.
66:48 Unfair challenge on Steve May by Shaun Hutchinson results in a free kick. Daniel Grainger takes the direct free kick.
65:01 Daniel Grainger restarts play with the free kick.
65:01 Substitution Robert McHugh on for Francis Jeffers.
65:01 Substitution Kevin Moon leaves the field to be replaced by Steve May.
65:01 Booking Booking for Steve Jennings for unsporting behaviour.
64:56 Free kick awarded for an unfair challenge on Murray Davidson by Steve Jennings.
62:41 Liam Craig has an effort at goal from outside the box missing to the wide left of the goal.
61:38 Foul by Shaun Hutchinson on Jordan Robertson, free kick awarded. Direct free kick taken by Daniel Grainger.
59:48 Jordan Robertson challenges Keith Lasley unfairly and gives away a free kick. Darren Randolph takes the free kick.
56:55 Foul by John Sutton on Steven Anderson, free kick awarded. Peter Enckelman takes the free kick.
55:40 Murray Davidson takes a shot. Darren Randolph makes a save. Corner taken left-footed by Daniel Grainger, clearance by Stevie
53:47 Steve Jennings gives away a free kick for an unfair challenge on Jody Morris. Daniel Grainger has an effort direct from the
free kick, save by Darren Randolph.
51:26 Stevie Hammell concedes a free kick for a foul on Jordan Robertson. David MacKay restarts play with the free kick.
49:15 Free kick taken by Darren Randolph.
49:15 Booking Jordan Robertson is shown a yellow card for unsporting behaviour.
49:08 Foul by Jordan Robertson on Shaun Hutchinson, free kick awarded.
45:25 Free kick awarded for an unfair challenge on Jamie Murphy by David MacKay. Stevie Hammell takes the direct free kick.
45:01 The referee starts the second half.
45:01 Substitution Collin Samuel leaves the field to be replaced by Jordan Robertson.
45:00+1:05 The ref blows to signal half-time.
44:52 John Sutton produces a right-footed shot from just outside the box that goes wide right of the goal.
44:21 Steve Jennings fouled by Jody Morris, the ref awards a free kick. Shaun Hutchinson restarts play with the free kick.
38:14 Assist by Francis Jeffers.
38:14 GOAL - John Sutton:Motherwell 3 - 0 St Johnstone John Sutton gets on the score sheet with a goal from just outside the penalty box to the top left corner of the goal. Motherwell
3-0 St Johnstone.
36:40 A cross is delivered by Jamie Murphy.
34:30 Effort from inside the area by Jamie Murphy misses to the right of the target.
34:09 Collin Samuel is ruled offside. Indirect free kick taken by Shaun Hutchinson.
32:44 Free kick taken by Stephen Craigan.
32:44 Booking Michael Duberry is shown a yellow card for unsporting behaviour.
32:40 Michael Duberry gives away a free kick for an unfair challenge on Keith Lasley.
31:59 Francis Jeffers challenges Steven Anderson unfairly and gives away a free kick. Peter Enckelman restarts play with the free
31:16 Foul by Daniele Invincibile on Stephen Craigan, free kick awarded. Direct free kick taken by Stevie Hammell.
30:46 Effort on goal by Keith Lasley from deep inside the penalty area misses to the right of the target.
28:28 Daniel Grainger takes the inswinging corner, save by Darren Randolph.
27:30 The ball is delivered by Jody Morris, Steve Jennings manages to make a clearance.
25:53 Free kick awarded for an unfair challenge on Daniele Invincibile by Stephen Craigan. Free kick crossed left-footed by Daniel
Grainger, Tom Hateley manages to make a clearance. Outswinging corner taken from the left by-line by Daniel Grainger.
24:23 Free kick awarded for an unfair challenge on Murray Davidson by Francis Jeffers. Peter Enckelman takes the free kick.
23:32 The assistant referee signals for offside against Collin Samuel. Indirect free kick taken by Darren Randolph.
22:17 Effort on goal by Murray Davidson from a long way out goes over the bar.
20:03 Free kick awarded for an unfair challenge on Collin Samuel by Shaun Hutchinson. Daniel Grainger takes the direct free kick.
18:48 Unfair challenge on Collin Samuel by Stephen Craigan results in a free kick. Free kick crossed left-footed by Daniel Grainger,
clearance by John Sutton.
17:59 David MacKay produces a cross, Daniel Grainger takes a shot. Tom Hateley gets a block in.
17:27 A cross is delivered by David MacKay.
16:20 The ball is swung over by Michael Duberry.
15:29 Foul by Shaun Hutchinson on Collin Samuel, free kick awarded. Daniel Grainger takes the direct free kick.
13:31 The assist for the goal came from John Sutton.
13:31 GOAL - Jamie Murphy:Motherwell 2 - 0 St Johnstone Jamie Murphy finds the net with a goal from just outside the box to the bottom left corner of the goal. Motherwell 2-0 St
12:12 Unfair challenge on Jody Morris by Francis Jeffers results in a free kick. Direct free kick taken by Michael Duberry.
8:59 Michael Duberry concedes a free kick for a foul on John Sutton. Free kick taken by Stevie Hammell.
6:59 John Sutton gives away a free kick for an unfair challenge on Michael Duberry. Free kick taken by Peter Enckelman.
6:14 Unfair challenge on Francis Jeffers by Murray Davidson results in a free kick. Stevie Hammell takes the free kick.
4:04 Tom Hateley provided the assist for the goal.
4:04 GOAL - Stephen Craigan:Motherwell 1 - 0 St Johnstone Stephen Craigan scores a headed goal from inside the six-yard box. Motherwell 1-0 St Johnstone.
3:32 Inswinging corner taken right-footed by Tom Hateley from the left by-line,
1:21 Michael Duberry fouled by Francis Jeffers, the ref awards a free kick. Daniel Grainger produces a cross, Daniele Invincibile
takes a shot. Save made by Darren Randolph. David MacKay takes a inswinging corner from the left by-line played to the near
post, Jody Morris takes a shot. Blocked by Steve Jennings.
0:55 David MacKay sends in a cross, clearance made by Stephen Craigan.
0:00 The ref blows the whistle to start the match.
Live text and data provided by The Press Association.
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