Match ends, Dundee United 0, St Johnstone 1.
A mistake by Dundee United goalkeeper Radoslaw Cierzniak helped hand St Johnstone the points at Tannadice.
Gary Mackay-Steven and Nadir Ciftci both passed up early chances before Stevie May's innocuous 30-yard shot squirmed through the Pole's fingers.
Both Jackie McNamara and Tommy Wright were sent to the stand as tempers frayed in the dugout after Farid El Alagui went down in the box.
Mackay-Steven also had a second penalty claim waved away in stoppage-time.
The result means St Johnstone now pull four points clear of Hibernian in the race for a place in the Scottish Premiership's top-six.
It was Wright's side who dominated the early exchanges much to the surprise of the hosts, threatening four times in the opening 10 minutes.
Gary McDonald headed David Wotherspoon's near-post corner wide then Cierzniak had to push May's shot wide after a long ball had caught out Gunning.
Keith Watson scrambled clear Michael O'Halloran's cutback in the six-yard box before May again had an opportunity when he volleyed over from 14 yards.
As the half wore on, United improved and had two great opportunities to net the opener.
Mackay-Steven rounded Alan Mannus but took a touch too many, giving Dave Mackay the chance to get back and block the shot.
Three minutes later, Nadir Ciftci passed up an even better chance, shooting weakly when given a free shot at goal.

It was a soft goal from May that broke the deadlock just after the restart. Cierzniak looked like he had the St Johnstone striker's effort covered but took his eye off the ball and saw it slip out of his grasp and over the line.
That livened the game up. Mannus saved Ciftci's header and pushed away Ryan Dow's strike before May's looping header landed on the roof of the net.
United threw on El Alagui and Ryan Gauld for the last 20 minutes and both were involved in controversial moments that led to the dismissal of both managers.
The home side felt they should have had a penalty when El Alagui hit the deck after a shoulder-to-shoulder challenge from O'Halloran. Referee Crawford Allan took a good look then decided against pointing to the spot.
When that was followed by Gauld's jinking run being halted abruptly with no free-kick awarded, the United bench reacted furiously, sparking a touchline row between the opposition managers.
Mannus made a point-blank save from El Alagui following Andy Robertson's low cross before Saints survived another penalty claim when Wotherspoon challenged Mackay-Steven in stoppage time.
The defeat means the Tannadice men drop to fifth in the table as they battle for a European spot and brings to an end a run of five consecutive victories.
Line-ups
Dundee Utd
Formation 4-2-3-1
- 1Cierzniak
- 12Watson
- 26RobertsonBooked at 77mins
- 8Rankin
- 2DillonSubstituted forGrahamat 85'minutes
- 5Gunning
- 10S ArmstrongSubstituted forEl Alaguiat 66'minutes
- 6Paton
- 21CiftciBooked at 74mins
- 18DowSubstituted forGauldat 66'minutes
- 11Mackay-Steven
Substitutes
- 9Graham
- 16Wilson
- 19Gauld
- 20Souttar
- 25McCallum
- 27Gomis
- 29El Alagui
St Johnstone
Formation 4-2-3-1
- 1Mannus
- 19MillerSubstituted forCreggat 90+1'minutes
- 24EastonSubstituted forClancyat 21'minutes
- 8McDonald
- 2MackayBooked at 68mins
- 6Anderson
- 29O'HalloranSubstituted forCroftat 83'minutes
- 12DunneBooked at 80mins
- 17MayBooked at 90mins
- 7MillarBooked at 77mins
- 10Wotherspoon
Substitutes
- 4Cregg
- 11Hasselbaink
- 15Banks
- 20Brown
- 22Croft
- 23Clancy
- 25Iwelumo
- Referee:
- Crawford Allan
- Attendance:
- 6,720
Match Stats
- Possession
- Home50%
- Away50%
- Shots
- Home8
- Away10
- Shots on Target
- Home4
- Away3
- Corners
- Home5
- Away5
- Fouls
- Home17
- Away17
Live Text
Post update
Full Time
Second Half ends, Dundee United 0, St Johnstone 1.
Post update
Corner, Dundee United. Conceded by Steven Anderson.
Booking
Steve May (St Johnstone) is shown the yellow card.
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Gavin Gunning (Dundee United) wins a free kick in the attacking half.
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Foul by Steve May (St Johnstone).
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Brian Graham (Dundee United) wins a free kick in the defensive half.
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Foul by Steven Anderson (St Johnstone).
Substitution
Substitution, St Johnstone. Patrick Cregg replaces Gary Miller because of an injury.
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Foul by Andrew Robertson (Dundee United).
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Lee Croft (St Johnstone) wins a free kick on the left wing.
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Attempt missed. Steve May (St Johnstone) left footed shot from outside the box misses to the right.
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Gavin Gunning (Dundee United) wins a free kick in the attacking half.
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Foul by Steve May (St Johnstone).
Substitution
Substitution, Dundee United. Brian Graham replaces Sean Dillon.
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Attempt missed. Nadir Ciftci (Dundee United) right footed shot from outside the box is close, but misses to the left.
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Attempt saved. Gavin Gunning (Dundee United) left footed shot from outside the box is saved in the bottom right corner.
Substitution
Substitution, St Johnstone. Lee Croft replaces Michael O'Halloran.
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Nadir Ciftci (Dundee United) wins a free kick in the defensive half.
Post update
Foul by Gary Miller (St Johnstone).