Livingston climbed up to fourth in the Premiership table after taking full advantage of a woeful defensive display from St Johnstone - only to almost throw away a three goal advantage in Perth in a 4-2 victory.
The Lions looked likely to find the net every time they ventured forward in the opening 45 minutes with an abject Saints defence meaning they were fortunate to find themselves only three down at the break.
A near identical Stephen Kelly early double - firing the first home from distance after jinking beyond a lunging defender before wonderfully sweeping home no.2 when both he and Nicky Devlin - who set him up - were given acres of space.
James Penrice made it three just before the break when he turned home from close range after the Perth outfit failed to deal with a corner when given multiple chances to clear.
But a quick-fire double from Jamie Murphy and Connor McLennan around the midway mark of the second-half - both tapping home after Shamal George parried initial efforts - made for a nervy finish with the pressure only alleviated when Penrice smashed high into the roof of the net with nine minutes remaining to kill the game off.
Livi boss David Martindale elected to make no changes to the side that defeated Ross County in Dingwall last weekend.
Saints went into the clash on the back of four straight defeats but started brightly. Ryan McGowan's flicked effort went narrowly over the bar in the opening minutes, while Nicky Devlin was at full stretch to make a pivotal interception on the edge of his six yard box.
But such is their luck right now that Livi opened the scoring with their first chance on eight minutes. Stephen Kelly showed wonderful composure to avoid a lunging defender and switch the ball from right foot to left before angling a drive beyond Remi Matthews from 20 yards.
The former Rangers youngster was at it again seven minutes later as Devlin was played in behind the defence on the right flank with his cutback being expertly swept home to double the lead.
The home side struggled to get into the game following that early double setback but they would have reduced the deficit on a rare foray into the Livi box around the half-hour mark if not for an instinctive claw off the line from George to deny Clark.
Their defence could barely put a foot right and it appeared only a matter of time before the Lions would add to their lead. The third duly arrived six minutes before the break as James Penrice neatly flicked the ball home from close range.
Callum Davidson's response was a triple change at the break with Jamie Murphy, Cammy MacPherson and Connor McLennan introduced but the first-half display left them with far too high a mountain to climb.
But they vey nearly managed. A much more composed display after the break produced little in an attacking sense until a dramatic double in the space of two minutes made it very much game on.
Sub Murphy gave St Johnstone some hope when he slammed the ball into the net on 65 minutes after George had made a smart save to deny Nicky Clark. That sparked the hosts into life and they instantly cut the deficit further in near identical fashion with McLennan being the beneficiary of Livi's slack defending on this occasion.
That made for a backs to the wall defensive effort for the away side as Saints piled on all the pressure and were virtually camped inside the Livi half but they failed to make it count and the Lions ensured they returned to West Lothian with the points in the bag as Penrice slammed high into the roof of the net on 81 minutes before comfortably seeing out the final stages.
St Johnstone: Matthews; Mitchell (MacPherson 45), Gordon, Considine; Wright, Carey (McLennan 45), McGowan (Phillips 50), Montgomery; Wotherspoon (Murphy 45), May; Clark (Bair 75). Subs not used: Parish, Brown, O'Halloran, Crawford.
Goal: Murphy (65), MacLennan (67)
Livingston: George; Devlin, Boyes, Fitzwater, Penrice; Se. Kelly, Omeonga (Holt 70), Shinnie (Pittman 70); Bradley, Anderson (Guthrie 75), St. Kelly (Obileye 83). Subs not used: Hamilton, Longridge, Bahamboula, Goncalves, Montano.
Goal: St. Kelly (8, 15), Penrice (39, 81)
