IT is a stated aim of chairman Dave King for Rangers to win one of the national cup competitions this season but just perhaps a few targets were being hastily redrawn in the Ibrox boardroom last night. All that hypothesising about how this swashbuckling Rangers side would fare were they stationed in the Ladbrokes Premiership rather than the Championship was given an answer of sorts last night by this imperious St Johnstone performance which did for their League Cup ambitions. You can read too much into one result - many wrongly assumed that things augured well for Ally McCoist's side when they won 1-0 here against the same opponents last October courtesy of a Lewis MacLeod header - but the seventh best side in Scotland on current form came to Govan and did an absolute number on Mark Warburton's side.

After eleven league wins a few of the first cracks in the Ibrox edifice began to show but all most visitors could do was sit back and admire the efficiency which the away side had displayed, led by their tormentor-in-chief Michael O'Halloran. As they trooped off the pitch in celebration, a decent number of supporters in the main stand stayed behind to applaud them off the park, a fate which used to be reserved for top European sides on Champions League nights.

While Mark Warburton restored Rob Kiernan, Jason Holt and Nathan Oduwa to what could be classed his strongest team so far this season, Tommy Wright had welcomed back former Rangers striker Steven MacLean after he had been excused Saturday's Ladbrokes Premiership match with Kilmarnock to prevent damage being inflicted on his knees by the aritificial surface at Rugby Park. The Perth side lost that match 2-1, continuing their patchy early season league form, but the bullk of this group won the Scottish Cup for this side in May 2014 and their ambitions of doing the same again in the League Cup this season live on after this one.

Wright had clearly done his homework and his masterplan when it came to halting this buccaneering Rangers side revolved around keeping the quicksilver O'Halloran up the park to penetrate the spaces left by the forays of full backs James Tavernier and Lee Wallace. It worked a charm, with the likes of David Wotherspoon, Chris Millar or Simon Lappin picking the right pass to move the Perth side from defence to attack in an instant.

Lappin's prowess with his left foot has carried him all the way to Norwich and Cardiff and it provided the first glimpse that this one wasn't going to pan out the way Rangers had hoped. A long throw from Joe Shaughnessy was attacked by one-time Ibrox target Murray Davidson, but only dropped to the 32-year-old on the edge of the box. Wes Foderingham was down smartly to beat his effort wide of the post.

A blistering, weaving 50-yard run from O'Halloran which took him past four men was another indicator of his threat, but the former Bolton man slipped on the greasy surface just as he was preparing to make the final pass. Such frustrations were forgotten about when he got down the right this time, and MacLean's cute flick played in Davidson, who guided the ball into the bottom corner.

The small band of Saints fans in the corner burst into life and they so nearly had a second to celebrate within minutes. Wotherspoon fed O'Halloran down the right again and, with the goal gaping, MacLean somehow contrived to hit the ball over from a yard.

The unwritten laws of football suggest that such profligacy is instantly punished and it nearly materialised when Kenny Miller tested Mannus with a left foot shot, but St Johnstone weren't done yet.

Not by a long chalk. Lappin was allowed to tip toe to the edge of the box to receive a short Wotherspoon corner and his strike was true. It fairly flew into Foderingham's bottom corner.

The shellshock around Ibrox reached its apex two minutes into the second period. That was when MacLean collected a long pass, and slung it into the space behind Rangers' central defenders. The manner in which O'Halloran took yards off Wilson and Kiernan before placing a low finish behind Foderingham must have alarmed the Ibrox technical area.

Throughout all this it seemed incredible to point out that the Ibrox side hadn't actually played too badly on the night, just perhaps played in too open a manner. The spark they needed to get back in the game almost came from Nathan Oduwa, who skipped into space before firing in a shot which caused the bar to reverberate. Dean Shiels, on for Jason Holt, also made an impact.

If this was a first sign of some of these Rangers players in adversity, a spirited response told a story. It was another feather in the cap of Tavernier that he played like a man possessed in such circumstances and he gave the Ibrox side a route back into the game just after the hour. Found by Oduwa, he worked a yard away from the visibly tiring Lappin and fired an unstoppable right-foot drive into the top corner.

For a spell, St Johnstone were on the ropes but Wright wisely freshened his personnel with the addition of Liam Craig and Graham Cummins and soon the momentum had petered out. The Ibrox side's league momentum will recover from this but their chairman's hopes of a national cup win will now be confined to the Scottish Cup.