A controversial Brian Graham penalty gave St Johnstone a 1-0 win against 10-man Caley Thistle at McDiarmid Park.
The Perth Saints attacker looked to have gone to ground too easily when attempting to round Inverness goalkeeper Dean Brill but referee Brian Colvin pointed to the spot.
Graham sent Brill the wrong way to net the game’s only goal with Caley Thistle ending the match with 10 men after Ross Draper was red carded.
Inverness, who had won their previous four matches against the Saints, made two alterations from last week’s 4-0 defeat to Partick Thistle with Aaron Doran and Ryan Christie drafted in for Danny Williams and Marley Watkins.
In-form St Johnstone, who were aiming for a fifth consecutive win, were missing James McFadden because of a hamstring with Lee Croft returning in his absence.
Ryan Christie was one of the few bright sparks in a forgettable first half and the young attacking midfielder drew the first save of the match from Saints stopper Alan Mannus with a curling effort from the edge of the area.
The visitors had a fortunate escape three minutes before the break when Steven Anderson nodded the ball into the path of captain Dave Mackay whose low drive flew through the legs of Dean Brill but was hacked off the line by Graeme Shinnie.
The Saints made the breakthrough in controversial circumstances when Graham netted from the spot with 63 minutes on the clock.
And things quickly went from bad to worse for Inverness went Draper was shown a red card for a challenge on Simon Lappin four minutes later.